20 - 30 minuten
Noticed my battery life was significantly diminished compared to when I bought it 2 1/2 years ago. I could sit and watch the battery meter "count down" from 100% to 10% in a matter of 3 hours. As an electronics tech, I figured I'd spend the $20 on the battery kit rather than fork over the hundreds of $$$ for a new phone.
Received the battery, and following the Guide, was able to have it back up and running in about 30 mins. Performed the "surgery" while at my desk at work. I forgot to bring a suction cup, as recommended in the Guide, but was able to separate the screen using some duct tape. The spudger was invaluable for getting to the smaller connectors, and the guide was extremely detailed.
My only suggestion is to include the suction cup in the kit, or make sure you have one prior to attempting. Although the duct tape method worked, it peeled off my screen protector. No big loss as I have an Otterbox. If you watch the video, and follow the guide, almost anyone can perform this repair. Thanks iFixit!