My phone had slowed down and the battery needed recharging throughout the day.
I had so much fun! The instructions were excellent and easy to follow. The only glitch, other than having a tab break and having to use a hair dryer and a credit card to remove the battery and taking time to find a magnifying glass (hence the two hours), was that the 1.7 mm battery dropped into the phone and I couldn’t see well enough to be sure where it was and couldn’t get it out. I put the phone back together anyway, and it worked! Except the Touch ID no longer functioned. The next morning it still worked. But later that day the home button stopped functioning. Fail!
The next day a visiting engineer friend found the missing screw inside the phone after I opened it and detached the cables, and he also noticed that I had stretched a cable. He easily fixed it and the phone now works in every way and is fast and the battery lasts all day or more. This whole project was so much fun for me!
Be very very very slow and patient when pulling the elastic tabs. Also have a good magnifying glass at hand—everything is tiny!