Thanks a lot for this guide! Some advice from me.
1. When doing step 4, gently pull the plate towards usb connector to take it away.
2. The little round glass that protects the camera and is situated on the plate may fall off, so check for it.
3. Display cable -- DO NOT pull it. After you disconnected all the cables but this one (number two), gently lift the green board and turn it upside down. The place of connection has a little white plug. Very gently move it into upright position (DO NOT tear it away from the black box it is attached to). When assembling, insert the new display cable there and put the white thing back in horizontal position.
4. Side buttons -- watch out, they may fall off.
5. The speaker -- in my case, it stayed on the old screen, so don't forget to put in this vital part. :-)
Also, you can switch the phone on to check all the connections while the plate is still unscrewed but hold the vibrating thing and the board with your fingers.
That's all folks!