IBM RT PC Options Installation page 25

mM 6151 System Unit
You need a medium-sized flat-bladed screwdriver to remove the system unit
cover.
CAUTION
This device is heavy. Two or more people should lift the system unit,
which weighs 25 kg (56 lb).
Do the following to remove the mM 6151 covers:
1. Turn the system off.
2. Turn any connected devices off.
1-10 Options Installation