IBM Aptiva Hardware Handbook page 138

5.
Remove the system unit cover:
a.
Remove the screws.
126 How to begin
(Back View)
b.
Slide the cover forward and completely remove
it from the system unit.
To prevent electrostatic charge from damaging
any part of your computer, touch the computer's
Important: bare metal frame before you unplug the system
unit, or wear an antistatic wrist strap while mak-
ing hardware changes.
6.
Unplug the system unit and monitor from the
electrical outlets.
7.
Unplug the power cords of any external options
from the electrical outlets.
(Front View)