Dell 4100 Service Manual page 45

To remove a computer cover, follow these steps:
1. Turn the cover's keylocks on the back panel of the computer to the
unlocked position (see Figure 4-2)
Figure 4-2. Keylocks on Computer's Back Panel
2. Loosen the three screws along the back edge of the cover (see
Figure 4-1).
3. Slide the cover toward the back of the computer an inch or so. Then
grasp the top of the cover at both ends, and lift it straight away from the
chassis.
.
keylock (2)
Removing and Replacing Parts 4-3