Battery was draining within 2 hours and % remaining was never accurate (at 100%) and then would die.
Super simple! Make sure that you have that pentalobe (?) screw driver.
My battery was taped in with double sided tape. And was very difficult to remove until I heated up the tape. I heated up a hot/cold pack and then set the phone on it for a few minutes. The battery came out very easily then and I got to reuse the tape as it stayed with the case.