After a few years, the iPhone 5 was not holding a charge very long. I lke the phone and the battery replacement kit was a lot cheaper than a new phone.
The repair want very smooth and easy. The hardest part was getting out the old battery -- the tab broke right off and I had to pry out the battery, but starting at the lower outside corner and taking my time did the trick.
The other challenge was the smallest screw -- the lower screw on the battery connector cover. That is HARD to handle. But it did go right in. I've never seen a screw that small before.
All in all, I would certainly do the battery replacement again.
I was surprised how easy the glass came off. The suction cup really works.
Take your time prying out the old battery. It is slow to start, but once started, comes right out.
Keep the parts well organized. There aren't many of them, but some are VERY small.