Replaced iPod Touch 1st gen battery
Dad never charges his iPod and then finds that a year later it wont turn on except when plugged in. Doesn't charge so it is basically a really expensive paper weight.
Used a razor blade and released all the clips in under a minute with no damage to the front or back case (its the fifth iPod that I've opened up/repaired).
In the guide they suggest removing the main board to desolder the old battery and solder in the new one, but it is unnecessary to do so (in fact it greatly increases the risk of destroying the iPod). You have access to the solder pads from the board while the it is still in the front case. Just be careful with your iron (I needed to pump mine up to around 800F because the case was acting like a heatsink) and don't heat stress the pads too much. Use a fine tip, flux, and minimal solder. A temp controlled iron makes life so much easier.