You do not break the rear 4 clips, simply insert an opening tool into the front (top side and bottom side) and slowly "walk it" open as you see being done in step #3.

Repeat, you do NOT need to break anything when you open up any device, if you think something is snapping, bending, or breaking, Stop and look for what you are missing with said repair.

as in this tear down, it should be completely silent, no popping of clips or rails.