Old iPhone 5s revived to life

My Problem

The battery was old.

My Fix

The repair was really straightforward, EXCEPT the for removing the battery adhesive!!

My Advice

I had to heat the phone to soften the adhesive (it's a cold 65 in our house), after the tabs broke off—like many others. Then I pried it with the prying tool very carefully. START FROM THE CORNERS. The battery was really bent up, but it went pretty quick. Heating really helps.