Success! New battery is in and the iPod works and looks as good as new (minus the bulge from the old swollen battery). My iPod is a 20 GB 4th Gen. Thanks for the detailed guide! Two thumbs up (although one is slightly scratched and both are tired from prying open the iPod). I agree with others that getting the case open is the toughest part of this process (30 minutes trying to get it open - 5 minutes to swap battery and get case back on). I used a plastic credit card - Qdoba rewards card :) - to slide down and open the tabs once I was able to wedge it into the side.