10 - 30 minuten
My iPhone 4S battery was not holding a charge very well anymore. I did not want to take it to Apple or anyone else because I already had experience with ifixit.com repair guides for Macbook Pro which were excellent instructions.
I chose to buy the kit with the pentalobe screwdriver which you need to get the original screws out. I took my time, followed the directions, and successfully replaced the battery without breaking anything. I have big hands and tend to break bolts on cars so for me I needed to go easy and slow and not over tighten anything. It took me about a 1/2 hour and the new battery is holding up quite well.
This repair was very easy. Just take your time and keep your attention on what you are doing. If you cannot see how things go together clearly, use a magnifying glass. I did, just to see closely how the little ground clip is supposed to fit. That is mentioned in the directions but as good as the photos are in the directions, I wanted to check it myself with some magnification in order to prevent damaging anything. It's a piece of cake job and saves you a lot of money plus you feel good for having fixed something yourself. Love it!
Ifixit is doing a great thing here. Cool company. Reasonable. I'm very happy you guys are around and have done all this work to provide us with great guidance. Please keep it up!