You may find that your microphone and/or your vibrator motor don't work any longer after putting the phone back together.

To fix the vibrator motor, remove the back again and pull gently on the spring contacts on the motor (which is attached to the back) to lengthen them a bit. When you put the phone back together, they should hopefully now make contact again.

Fixing the microphone isn't as easy. The approach that worked for me is documented in this YouTube video: https://www.youtube.com/watch?v=Af5DvIZw.... Instead of the thick tape, I used some fairly thin rubber material that I happened to have around -- it actually was excess from a card of stick-on rubber feet that I'd saved from some forgotten piece of equipment.