Whats involved with programing a keyless remote if I buy one on ebay?

http://myweb.accessus.net/~090/cfb-tech.html

Check this out, should guide you.

Alright, thank you so very much!

So I bought one, really wasnt to hard...my dad helped me.

Remote only works if Im right up at the door, and push it a couple times, I just replaced the battery too! Maybe the remote module?