We had an old iPhone 5 with a dead battery. The phone’s so cute I wanted to keep it and use it as a radio. With a new battery and toolkit (NZ$20), and the help of an excellent video, it took me 10 minutes to install the battery. 5 minutes were spent putting back 2 pinhead sized screws.

iPhone 5 battery replacement kit, tools and phone.
iPhone 5 opened up.
Fixed iPhone 5 with an app onscreen.