Remove these 4 silver 6mm Philips #2 screws to release the top power supply.

Peel off this cardboard that is glued to the power supply cover.

Unplug the large plugs at each end of the upper power supply and move the power supply out of the way. You can leave the smaller fan wire connected to the power supply.

Unplug this thin wire that connects the lid microswitch to the lower power supply so that the optical system is no longer attached to the power supply.