Number one: Commit
You are going to need to commit to letting go. Although you are not going to be able to let go of the hard feelings in a second, most likely not even in a day, you need to be serious about letting go. Letting go of the feelings of hurt can take you a long time to get over, but by recognizing that the pain is hurting you, you can being to move on.

Number two: Pros and cons
You are going to need to look at what kinds of problems the pain is causing for you. You want to ask yourself if the pain is affecting your relationship with the person you are upset with or even with other people. You want to look at the good and bad aspects of your relationship with this person, how you being upset with this person is affecting your life in a negative and positive way. You also want to think about the benefits of forgiveness, how it will make you feel better; improve your life and relationship.

Number three: You have a choice
You need to realize that you have a choice in deciding to let go of the hard feelings. You cannot control what other people do, nor should you try, but you can control your actions and thoughts. You need to stop reliving the pain and suffering that you went through. You need to use your power to move on with your life.

Number four: Empathize
Try putting yourself in your friend's position, trying, and figuring out why they did what they did. When doing this you have to assume that the person isn't a bad person, it's just that they did something wrong. You want to sit back and think about what could have happened in their life to make them do the things that they did. You want to try to understand their actions and empathize with them.

Number five: Understand your responsibility
Think back to see how you might have been partially responsible for everything that has happened. You need to look at the problem to see what you could have done to prevent it and what you can do to prevent it from happening again. This isn't saying that you need to take all of the blame, or taking responsibility away from the other person. This is making you realize that you are not a victim in most cases, but a participant in your life through the choices that you make.

Number six: Focus on the present
Once you have reflected on the past you need to realize that the past is over and it is no longer happening, except in your mind. By dwelling on the past, you are going to be focusing on the negative things that can end up causing your problems, such as undue stress. What you need to do instead is focus on what is happening right now. When you do start to think about the past, again you need to simply acknowledge that and bring yourself back into the present.