LOL! The reason they make it hard to service is that Apple Authorized repair wants $360.00 US to replace the battery!
This repair guide is missing the instructions for actually replacing the battery! It does not cover the actual disconnecting of the old battery or the reconnection of the new one. Perhaps this is the easiest step, but it still should be included, since that's the whole objective of this repair! I personally have never disconnected an iPod classic battery, nor have I ever connected a new battery in one. How do I know there isn't some particular tricky aspect to the battery connection? To goof up this final step would be a real shame after going through so much trouble to preserve the integrity of the iPod's case that you don't even give any instructions about the battery!