IBM RT PC Options Installation page 31

9. To remove the left side cover:
a. Find the tab under one outside edge of the left-side cover.
Push up on the tab until it is free of the hole in the cover.
b. Do the same to the tab on the other side.
c. Rotate the cover out, away from the bottom of the unit.
d. Lift the side cover up until the hooks are free of the loops in
the top of the unit.
Section 1. Getting Started 1-9