I was having an issue where my iPod classic would only run about 2 hours before going dead. I would charge it all night and the battery meter would say fully charged but would be dead in a few hours just listening to music. Feeling frustrated , I checked with apple and they said I could take to an Apple Store and get a new battery installed for about $80. I thought that was a little high so searched the web for other alternatives. That's when I found "ifixit". Read the reviews and instructions and figured I could replace the battery myself for about 1/4 the cost of an Apple Store and an hour drive to get there. So I ordered the kit and had it shipped to my house.
I received the kit from "ifixit" within a few days. In the kit is a better and two soft tools for taking the iPod apart . I then pulled up the "ifixit" videos and followed the directions. Presto- new battery installed and working like a brand new one!
Be sure to watch the videos on the repairs and the biggest thing is to be patient! It will seem like the iPod will not come apart but just keep working with it and it will . My total repair time was about 45 mins. That was due to taking it apart and getting the old battery out. The glue holding the old one in took a little extra time to remove. Well worth the time and money to do yourself . If I can do it, so can you. Don't rush and take your time .