same here. one screw was completely absent on mine, and the other two couldn't be put back. I probably broke one of the tabs while reassembling the device. it still works fine, but I don't really like how loose the casing feels now.

I highly recommend just using some double-sided tape to re-attach the new battery. The old one was a complete pain in the butt to remove. the battery adhesive is almost as annoying as the rear glass adhesive.

yeah, the coil assembly may take this off for you. pay attention!

Yeah, for more detailed instructions, check the battery replacement guide and refer to steps 9 through 11.

It took about 3 minutes on my 90 C printbed to get the first pick in. If the suction cup gives up before the adhesive does, try using some Isopropyl alcohol to clean the back of the phone, and it should stick better. Also, don't apply heat to the screen, just in case that wasn't clear.

Don't Forget Step 0! Turn the phone Off and remove the SIM card tray. just to be safe, I'd recommend making a full backup of your phone onto a micro SD card in case the worst should happen. also, make sure anyone who needs to contact you knows you aren't currently available at your phone number.