I had an IPod Nano 4th Generation that just died. No resetting, button-pushing, or plugging it into a computer or wall charger would bring it back to life. I had several audio books that weren't backed-up anywhere else that I really wanted to rescue (long story).
I'm a skilled DIY'er who fixes my own computers, vehicles, motorcycles, house stuff, etc.... The repair was definitely tough with lots of tiny parts--mostly the precision soldering work to re-attach the new battery. I used the Ifixit guide combined with some video guides on youtube. Lots of fragile cables, and parts stuck-on with adhesive to deal with. In the end, it works well enough for me to plug it into the computer and rescue the files I wanted to save, which was all I really needed. The click-wheel doesn't seem to want to work (or it's possible that the hold button has shifted and is stuck in "lock" position), and the end covers won't stay adhered.
This is a good product with a solid installation kit. I used a tiny flat-head metal screwdriver in addition to the supplied tools, which helped a lot. Also make sure that the very tip of your soldering iron gets hot enough to work with. My experience is that if I really wanted to save the I-pod for future use, I'd be tempted to take it to professional repair place. I felt good about what I did, but it's not really playable now--it may be that the hold button has shifted away from the switch and is stuck in the lock position. There are a number of adhered parts that just didn't want to re-stick. If the kit contained a bit of adhesive (or maybe just plan to use a few drops of super glue), that would help. Ultimately, I was able to rescue the files that I wanted for $15, so I'm happy with the purchase and time spent.