10 - 30 minuten
My iPhone4s is about 18 months old. I use it to track my steps, mileage and routes when exercising/running. In the past half year, I have noticed that the battery drains faster and faster. I have a small external battery recharger, but that is clunky as I end up with two objects, connected by a cable, in my pocket. Rather than having to charge my phone 2x or 3x per day I looked at just replacing the internal battery.
The order arrived within a week. The total repair, counting drinking a cup of coffee, took less than 15 minutes. The guide, as previous iFixit guides I have used, was excellent and easy to follow. I opted to not replace the factory Pentalobe screws with the supplied Phillips as I want to most likely trade in my phone next year.
iFixit makes many repairs easy. The guides are all very well organized and clear. I have talked to some others who have gotten parts elsewhere for a little less, like from eBay, but have ended up being disappointed in the false economy. I heartily recommend iFixit to the rest of the staff in my University's IT Office, and they have been using it quite successfully in repairing the many different devices that come in to us for work.