Epson 3865X Plus - Manual (Page 110)

5.
6.
Turn the computer around so you are facing the back panel.
As shown below, the cover is secured by a large screw on
the back panel. Turn the
screw counterclockwise to unlock
the cover.
screw
The cover is also secured by two latches on the back of the
cover near the corners. Press both latches inward and then
lift up the cover from the back panel. You might meet some
resistance from the grounding tabs along the inside of the
cover.
latches
Installing and Removing Options 5-3