15 minuten - 1 uur
My original iPhone 5 battery was running down quickly - if I didn't have it plugged in most of the day the battery would go dead, and quickly. I bought an external battery (non-iFixit) to help, but it helped only when I remembered to have it on me.
Repair went well - I watched the Youtube instructions a few times, and then did the replacement along with the Youtube video. I knew that the adhesive on the original battery could be an issue, but it really wasn't since I followed the iFixit instructions exactly.
End result - my iPhone now holds a charge like it did when I first bought it. Sure beats watching the battery drop to 30% between driving from work to home as it did prior to the replacement :-)
A few things to note - I got the iFixit iPhone 5 battery repair kit (came with the necessary screwdrivers etc) - definitely a good idea to get the kit unless you already have the two odd screwdrivers needed.
As the video said, prying open the iPhone 5 was the "hardest" part of the process - just to get the right pull with the suction cup to get the plastic tool in between to start the pull - once that happened it was easy. But follow the video - don't just yank the top off since you need to disconnect a few cables to do the replacement safely.
The most frustrating part was actually getting the three screws on the plate over the cables back on. The screws are so tiny it took me some time to get the screws back in the holes. But once there I had no issues.
I did also buy the magnetic mat. Having recently done some laptop maintenance (separate from this) it was a challenge to keep the screws organized. The mat would have been handy for that work. At least the mat was very helpful for the iPhone battery replacement.