15 minuten - 1 uur
My iPhone 5's battery was behaving erratically for a few weeks, it would reach 20% and die within minutes from there. When I had the time to take it to Apple, they asked me for $79 + tax and even though it was 3-4 weeks over my warranty, they didn't want to offer anything to me. I was like if I am going to spend close to $90 on a battery, I could just buy another used iPhone while I waited for my upgrade.
I looked online and saw batteries starting at $7 on Amazon, but I remember using iFixit in the past to repair my Macbook so planned to check it out. The deal was more expensive than the $7 battery but I felt easier trusting iFixit over some random seller.
Wasn't hard at all, the recommended tools were appropriate and the instructions super simple! I am glad I went with iFixit rather than Apple!
For the pair of screws inside the phone the left and right screws near the display and the battery were of different size even though they weren't noted as such so I had to make sure I remembered which one was shorter - clarifying that further would be perfect.