Motivation
The most important aspect of recovery is motivation - full recovery from an eating disorder takes an average of 7 years. A person has to be ready for recovery and be prepared to change their entire life, rewire all their habits and thoughts, change their entire identity, work harder than they ever had before. All too often people with EDs try half-hearted recovery and because it doesn't work out they give up on it. Often they'll try to please others, maybe just on a whim - it's not enough. A person has to try and try and try, not give up, be determined, be ready for let-downs and hard times, be prepared to modify their strategy over and over, try new things.
EDs are almost always a coping mechanism for dealing with very difficult emotions and situations. A person cannot easily recover if they're going through a particularly stressful and difficult time because they will be relying on their eating disorder to give them some feelings of control and focus, and if one is stressed they will not be able to focus completely upon recovery. It is therefore best for full recovery to be started when the person is quite calm and stable. 

It is quite important before one starts that they should get a health check to make sure there are no urgent medical problems before progressing to change ones eating habits and lifestyle, because though the changes are beneficial they could be harmful if someone is sick and needs specialist care.

Behaviours
The first step to recovery is to tackle individual addictive ineffective behaviours - mainly purgeing, laxative abuse, drug abuse, excessive exercise, some bingeing. Motivation to tackle these can be gained from the knowledge that most of them are completely ineffective for weightloss and in many cases inhibit weightloss as well as being dangerous to ones health. Dangers and effectiveness of the various ED behaviours are written on here and tips for overcoming certain behaviours are written here. The hardest behaviours to kick are restricting (and fasting) and bingeing, and these cannot be resolved at this stage easily. Other ED behaviours can be dealt with at later stages if they're too hard to eliminate at this stage.
This is a good stage to complete to help preserve some physical health if one is not psychologically ready for recovery.

Reasons
Throughout the process of recovery a person will go through hard times where they're tempted to revert to their old behaviour. To help combat this it is useful to have a list of strong reasons of why one truly wants to recover.
An example of some things on a list are:
- i want to enjoy my food
- i want to have children one day
- i'm fed up of always having a sore throat
- i want more time to do my school work
Other motivations can be useful too, such as photos of the person from times in the ED when she is really suffering.

Focus & Identity
With an ED the entire focus on ones life is upon the eating disorder. Thoughts about food/weight/etc are never far from the mind, and invade every aspect of the persons life and the ED behaviour holds presidence over any other activity. The ED takes over every part of the persons life, and by taking away the ED the person will be left floundering for some way to cope, something to focus their goals upon. As the ED takes presidence over everything else the ED becomes ingrained as part of the persons identity. They feel like an empty shell without their ED.
It's therefore a good idea for the person to find a new focus for their time, thoughts, and energy, such as a hobby, sport, learning something, etc. Something that they'd be proud to be linked to. This helps to build a new identity too.
It's also helpful for the person to remove labels they have for themselves such as "bulimic" because this engrains deeply into their identity. It's much healthier for such labels to be replaced with new ones such as "student" or "tennis-player".
It often helps to give the eating disorder a name (such as Mia) and view it as a person with a nasty personality who manipulates and harms the person, and as a completely seperate entity to the self, like a parasite.

Insight
It's a good idea for someone to have some understanding of where their ED comes from - what made them the way they are. This could involve certain events, certain people, certain experiences etc. 
Talking to others who have insight into their own illness, talking to a therapist, using art therapy, reading about theories of EDs, etc are all good ways of doing this.
Often people get discouraged when they have the insight because they may feel they cannot cope without the ED because they don't know how to cope with the issues raised. However, those who have worked through recovery have found it isn't a problem.

Communicate
Often people who suffer from EDs tend to be very secretive and lonely, and many psychiatrists believe EDs develop as a result of a lack of communication, especially in families. It's important to talk about ones feelings, most beneficial being face-to-face, but in a journal or to a friend or to a helpline are also good options.
It's also very helpful to communicate with others who are attempting recovery too - they are invaluable for good advice and for encouragement.

Triggers
Each person with an ED has certain things which when they're confronted with them causes them to feel tempted to revert to their ED behaviour and/or makes them feel bad about themselves. It is useful to know what these triggers are and to avoid them during recovery. It is hard to recognise when one is being triggered, so it is important for a person to analyse how they're feeling when doing certain things. Some examples of triggers are tight clothing, fashion magazines, other anorexics, diet books, celebrity gossip, thin friends, dieters, etc. 

Eating More
It is best for someone to make changes to their diet very gradually and to stick to "safe foods" initially. Taking one meal or snack at a time and modifying it to be a more ordinary is a good way to do it. A lot of anorexics and bulimics may need professional help from a nutritionist or therapist at this stage. 
It's a good idea to see how much other 'normal' people eat and to copy them, and some people find it useful to have set 'meal plans' to follow, though this isn't good in the longer term.
Many anorexics or bulimics will binge alongside their ordinary eating, and it is important that they don't get put off, though this is exceptionally difficult. The bingeing does stop however when a person is consistantly eating enough, has returned to their natural weight and is not bingeing by habit (watch out for this!).

Record
It is very helpful for a person to keep some form of record of their recovery in which they voice their concerns, feelings and successes. This can help them evalulate their progress, and if read by someone else any ED-distorted thinking can be challenged. Successes are particularly useful because these can be read back over when one is struggling as encouragement, and encouragement or pride from others is also very helpful.

Rules
Most anorexics and bulimics have certain 'rules' made by their ED, and these should be recognised and slowly broken down. Some examples of rules are "i must not eat carbs" "i should eat no more than 800cals a day" "i must exercise off all calories consumed" "i must only eat 8 grapes at a time" "i should not eat anything with more than 6% fat in" and very commonly "i must check the nutrition labels". Most of these rules inhibit natural healthy eating and the person should rebel against their ED and these rules.
A big part of the rules is "safe foods". A good way to break down rules is to eat foods that are not safe foods, by adding more and more foods to the "safe foods" list. The new additions can be increasingly daring and be a rebelling to the new rules. The person can see this as a fun challenge, trying new foods, and it can get quite enjoyable.

Thoughts
After all of this there will still be thoughts which can inhibit recovery and make the person feel bad about themselves. Often thoughts are overly negative, unrealistic or all-or-nothing. It's a very good idea for the person to recognise these thoughts and to change them to be more positive thoughts, for example omg i've gained 2lbs i'm so fat! should be changed to i've gained 2lbs, however i'm a healthy weight and even though this weightgain is distressing this bad feeling won't last. If a person has particular difficulty doing this herself it is helpful for her to have assistance, such as Cognitive Behavioural Therapy.

Remember
It is important to remember that recovery from an ED is possible, if only to an extent. Many believe full recovery isn't possible, however it is feasable to improve ones quality of life significantly.
ED recovery does not mean getting fat. Recovery involves returning to a healthy weight for ones height, not obesity, and with recovery ones perspectives change so that distorted body image isn't so pronounced.
Recovery is not a failure of willpower - recovery is 1000 times harder than bowing down under the demands of an ED.
Recovery is all about being happy in oneself and achieving psychological and physical health.