Battery not holding charge
In the end, it all went well. But it was REALLY hard to get the top face off, once the screws were removed. It took lot and lots of pulling with the small vacuum cup provided, and the plastic 'pry tool'. probably took me 20 minutes to get it off. Once it was off, everything else went ok, except that one of the adhesive pads broke right at the top, so I had to use the hairdryer and credit card approach. That worked, but it took a lot of maneuvering with the plastic card to get it under the battery. And the screws are REALLY, REALLY small and easy to loose.
1. Put a white cloth pad substantially bigger than the i-phone underneath it to catch the small screws if they pop out of the tweezers (which happens).
2. If you have to use the plastic card maneuver to get the battery loose (because one of the adhesive strips breaks before it is removed), make sure that it is thin plastic. There was no card in my replacement kit. I don't know that a really stiff card would work, as it needs to bend a bit to get underneath the battery.