10 - 30 minuten
My iPhone battery was dying really quickly under normal every-day use, and when it got down to around 30 percent my phone would decide it was dead and switch off. I had to be near a phone charger at all times. Very annoying.
This was my first time doing anything like this and I was a bit nervous, but I read the iFixit instructions several times, looked at the pics in full resolution, and read the user comments. I also watched a VERY helpful how-to video on youtube: https://www.youtube.com/watch?v=RW8RSA51...
I was worried about the mysterious, often-mentioned, and apparently troublesome "black ground clip" but in the video I saw exactly where it was and how to get it back in place if it escaped.
I used tweezers to manipulate the screws and little parts, to keep everything clean of finger oil.
I used an old plastic gift-card to pry out the old battery. It took a long time but I worked carefully and patiently, and eventually it came away from the adhesive.
The whole repair took maybe ten or fifteen minutes.
Watch HighTechDad's video and follow his advice:
Work on a towel under a bright lamp. Assemble all your tools ahead of time, including a plastic gift card and tweezers. Be slow, be patient, be careful, but don't be nervous. It's really not hard!
Thanks, iFixit :)