15 minuten - 1 uur
My iPhone battery failed when it got down to 20-30%. A couple of critical shutdowns and I decided to replace the battery.
The replacement went pretty smoothly. I referenced a YouTube video that was slightly different than the iFixit method. It didn't require the screen to be removed, which cut down the time it took and the number of screws removed significantly. I just had to rig up a backstop to keep the display from toppling backwards.
And I almost lost a screw from the bottom of the phone while trying to screw it back in. Those things are tiny! Be careful. Fortunately I found it after a diligent search.
The only other issue was when I tried to reattach the screen from the bottom first. It doesn't work. Work it from the top down.
Find a container to hold the screws and plate while replacing the actual battery. An empty contact lens case worked well in my case. Use the magnets in the screwdrivers to hold and position the screws when putting the phone back together. It's nearly impossible to do with fingers, at least for me. That's how I dropped and misplaced a screw.
Do the repair over a clean bare surface, and over a floor with linoleum or other smooth surface. In case a screw does make its wat to the floor you'll have at least a chance of finding it.