Recently I replaced the trackpad in a Macbook Pro. The pointer was jumping all over the screen and randomly selecting desktop items and opening them. After searching online for a while and trying a few things (like turning the computer on it's side and clicking) I decided it was probably a trackpad issue. I bought a trackpad off eBay for $35. Googling the repair, I found that the only tools you need are a tri-wing screwdriver and a small philips head screwdriver. Both of which I already had. If you don't have a tri-wing, they're super cheap on eBay.
So with the screwdrivers and trackpad ready, I opened up the macbook and replaced the trackpad. This fixed the problem and it's been working great for a month or two now. While I didn't actually replace the battery (it didn't need it), you have to physically remove the battery to get to the trackpad- the video also shows this process. Anyway I recorded it, edited it, and narrated it, and decided to share it. Everything you need to know is in the video.
I tried to make the narration entertaining. Thanks for looking!