I have been out of the Army since February of 2012. How do I appeal my disability compensation that I am receiving?

If its been more than a year since you received your VA decision letter then you cannot appeal. But you can file for an increase on your service connected disability. Just make sure you have medical evidence that shows your condition has become worse. I would suggest finding a VSO near you that can help you with your claim. You can fill-out the VSO Locator Form on my website and I will be glad to assist you.
http://www.disabledvetassistance.org/vso-locator.html

If you are referring to VA Compensation:

http://www.benefits.va.gov/compensation/

contact Dav they'll file it fore you

It's my understanding that you can do that directly from the VA benefits website. I've personally never tried it, but that's one of the options.

Though I do have a question, when you are given your disability rating, they literally tell you that you have 1 year to appeal the decision. So why wait so long to ask? Chances are they are going to reclassify you and make you go through all the poking and prodding and medical appointments you had to the first time.