Prepare clean lint free liner to cover diffuser stack after removal. I use thin garbage can liner.

IMPORTANT : Any crimp/fold/damage to these sheets will show up on display so handle with care. Avoid any finger print on the diffuser sheet. It is okay to handle from bottom of the white reflector sheet thats facing the tub

I removal the whole stack (3x diffuser sheet, plexi glass like lightguide and the white reflect sheet on the bottom) I recall there are corners near the LED bar that can lift the whole stack (will confirm in future)

Put stack down with white reflector sheet on the bottom on a clean surface. Cover top diffuser sheet with lint free liner.