Sharp PN-80TC3 Manuel D'installation page 12

nRemoving the Tray
Back of the tray
Attaching the speaker covers
n
If you will use the monitor in a portrait orientation, the speaker cover is not used.
Removing the tray mount fitting
n
If you will use the monitor in a portrait orientation or will otherwise not use the tray, remove the tray mount fitting.
10
E
(1) Pinch the locking tabs (4 places)
Speaker cover attachment screws (M3)
(2)