20 - 30 Minuten
The iPhone seemed to shut off at any random time with plenty of battery life left and would then reboot - maybe. Everything I have read indicated that a new battery was in order. So I found iFixit.
The ordering and delivery of the battery was uneventful which is great! the instructions and accompanying video were very helpful too. As with any repair that is new and unfamiliar, you don't know how much or little force is needed to detach, remove or reattach something so progress was slower than advertised - but thats ok.
Take your time and you will do fine. The included spudger is a bit weak. Mine broke very quickly, but there are two sides to it and the second one survived. I had to re-attach the face three times due to not connecting the chips properly, which I'll chalk up to inexperience. Now the phone is working great. Thanks iFixit!