Dell Dimension 2200 - Manual (Page 61)

Adding Parts 61
4 Face the front of the computer. Place your left hand on the left side of
the computer. Push back the release latch at the top-back edge of the
computer to release the computer cover into your left hand.
CAUTION: Keep your hands clear of the metal edges on the
computer.
5 Lift the cover out from the curved hinge at the bottom of the
computer.
release latch
computer cover