15 minuten - 1 uur
dead battery on a 6+ year old 4th gen iPod that was handed down to my daughter. it would take a 4-5 hour charge to get her 15-45 minutes of play time.
extremely easy, except for Apple's ability to make parts fit so incredibly well that they were difficult to find seams. I could take pictures as I did the repair on my lap and the arm of my couch, with the ifixit iPhone app open next to me (and a shirt pocket to hold the two torx screws). kudos on the app, btw. I loved that it didn't let the screen dim or turn off the entire time I used it for the repair guide.
instructions were very clear. and as stated, patience is the key. it does take several passes to part the seams initially. after that, it's just following directions. put back together in reverse order which literally took about 45 seconds. took longer to grab the screws from the bottom of my pocket than anything else.
as stated, patience in the initial prying of the case halves. they will come. perhaps consider a plastic butter knife or something that you can use in place of the spudger to pry well-holding battery adhesive. mine was put on very well and I was afraid I'd damage the tip of the spudger for a later use. and for the battery cable itself, I used a spudger to hold the seat and board down, while using some curved needle-nose pliers to grab the cable at the jack as it didn't seem to want to come either.