30 minutes - 2 hours
I had a problem with the battery. It would no longer hold a charge. While I was at it I decided to put in a new screen and hard drive. (Just to see if I could)
Could have been better. The videos I watched didn't quite explain how hard the back case was to take off. Other then that it was very simple.
Be extremely careful taking off the back case. It is the hardest part about the repair.
iPod Classic Color Display
iPod Classic (Thin) Battery
iPod Classic 120 GB Hard Drive
1.5" Thin Putty Knife