This is all you need... I fixed mine, and if I can do it, you can do it. I'm no hardware guy. Just take it slow.
http://forum.ppcgeeks.com/showthread.php?t=62876
They break easy because of poor design around the ribbon cable connection...once it's apart you'll see. Behind the battery is a thin piece of metal that isn't reinforced/attached...so if you press the battery in with even more than slight pressure (or even if the phone receives a MINOR bump), those ribbon connections can come off easy.
Suggest you have some electric tape/duct tape on hand to reinforce the connections once it's open.