I think what the 1st guy meant was that the drill/driver has a range of torque settings for driving screws, adjusted by turning the collar behind the chuck. This is used to prevent stripping or breaking the screw. When the torque is exceeded, the driver slips and makes a loud clicking noise. For drilling it is normally set to the highest setting.

This is just to replace the glass panel over the actual display/digitizer, is it not?

If this is right, why does one need tom remove the back of the case and “undo the metal clips”?

What about gluing the new screen in? It DOES need glue, does it not? Otherwise, what seals it from the environment?