Click Wheel didn't work - problem was old swollen battery
15 Minuten - 1 Stunde
The click button wasn't working - couldn't select anything from a menu even though the wheel worked. Looked around on iFixit to get a replacement wheel and button, but they're out of stock. Further looking on the web lead to a comment that sometimes this problem occurred because the battery was swollen and was pressing against the back of the button. Decided to give it a try.
Process was very smooth. Earlier I'd tried to open the iPod using a small jewelry screwdriver, but no joy. The tools that came with the battery worked easily. I did have to go out to buy a Torx T6 screwdriver ($5 at Home Depot, but you can also get it at iFixit). I ended up disconnecting the hard disk so that it was out of the way - easy to do but not part of the battery replacement guide. This made pulling the battery lead off quite a bit easier. Reassembly was easy too. The battery wasn't charged, so I had a scare when I tried to turn the iPod back on - nothing happened. Plugging it into the charge and all was well.
If you don't have a Torx screwdriver, you'll need to buy one. Radio Shack is expensive - look at iFixit or Home Depot.
Remove the hard drive. For me, getting the battery lead off was fidgity - didn't want to break anything but it does require some force. It was easier to do without having to hold the hard drive out of the way.