I finished changing the battery of my iPhone. All is Ok but I opened and disassembled my iPhone 3 times to succeed.
The manual is not badly done but disassembly is very delicate when it is the first time. It is not easy to go back because we do not know if we pushed the connectors well, the handling of the screws which are very small is very delicate.
To be honest, I understand Apple to put special screws to close his iPhone because it is very risky to disassemble and discourage the general public is a good idea.
It is always easy for anyone who wants to buy a suitable screwdriver.
Last observation, I do not criticize Apple to stick its battery but I criticize the amount of glue it puts. It's way too much and it feels like she's doing it on purpose ...