My 2010 white unibody 13" MacNook's battery was failing even faster than my iPhone 4's, and I didn't want to pay a king's ransom to Apple to fix it. I was miffed the battery had failed so fast... but maybe I shouldn't have left it on charge for months!
The repair was straightforward - I would never have known about the 'hidden screw' under the battery warranty label tho, thanks iFixit! The Y1 screws holding the battery in place would not 'go back in' so I needed to disassemble my Mac a second time to get a snugger fit as the trackpad lost its click... all good now.
I would have taken more care removing the battery screws as they simply wouldn't go back in - they don't 'marry up' properly so I am running the MacBook without the battery being screwed in... with no problems I hasten to add.