Il Mio Problema
1.The speaker had fine steel chips in it, that caused it to loose its' volume.
2. The back was badly scratched on the camera lens.
La Mia Riparazione
1. I used the 4, 4 CDMA, and the 4S pictorials. It was not necessary to remove the on / off switch.
2. The new back was exceedingly tight, to slide all the way into place.
Well! It fired up correctly the first time.
Il Mio Consiglio
Maybe to put an ink mark on the clip that coverts the camera, so you remember the direction it fits in.