How to Forget About Your Ex Boyfriend

Get rid of all of his belongings. 
Football sweaters, presents, CDs, pictures, anything that reminds you of him. Take everything and throw it away (or give them back to him, if you're feeling generous). It may hurt knowing that those were the only things you had left of him, but you should also know that it's the right thing to do. You will feel a sense of accomplishment after you do this and it will be you first step towards healing.
Think about all of your good qualities.
 Make a list of what you love about yourself. When you are done with that list, make another one of all the bad qualities of your ex. Look at both of them and let yourself draw the conclusion that he doesn't deserve you, and that your separation was necessary. You will have more self-confidence knowing that your ex is really a jerk or a pig. You will be thankful that you broke up with someone that has the qualities that make him an unfit boyfriend.
Don't dwell on the good times. 
You can reminisce about these once you've moved away from everything else that reminds you of him; eventually, they will be fond memories, but right now they're just going to remind you of him. So instead, think back to your fights and all the times you have wanted to break up with him. Remember that no one has the right to take over your life and don't let him do that to you, especially now!
Seek support from your friends and family. 
This will allow you to feel better and quicken the healing process. No matter how gloomy you feel after your relationship ends, sometimes a little bit of fun is the perfect remedy for a fractured heart. So go shopping, go to the movies, have a slumber party, etc. Taking your mind off of things is guaranteed to lift your spirits, even if it's only for an hour or two.
Feel confident. 
You're past this romantic disaster and you might even want to think about starting to date again! Additionally, now that you've cleansed yourself of all remaining attraction to your ex, you should talk to him a little, ask about being friends again. Do not do this, however, if there is even the slightest bit of lingering passion. Hooking up with him again will undo all the progress you've made, even if you tell yourself that it's the last time. Remember, bigger and better things! He's obviously not good for you, so if you start to feel yourself slipping into old habits, avoid him like the plague.