My battery was not lasting very long
The detailed instructions were great. Because there were so many little screws, I bought the ifixit anti static project tray. It did a good job of helping me organize all of the parts.
Everything was fairly easy, except for two things. When I pulled out the tape, the second piece broke. That lead to some tense minutes prying out the old battery. Fortunately, it was a success. Then, the last cable for the home button was tough to get in. Overall, I was happy. It was worth the work. My battery life is much improved.
Take your time pulling the tape out. If it breaks, the job becomes much harder.