Dell Precision 7920 Owner's Manual page 12

CAUTION: The system will not power on while the side cover is off. Also, the system will shut down if the side cover is
removed while the system is on.
2 To remove the side cover:
3 Press the latch
4 Pull the latch [1] upward and rotate it to release the cover [2].
5 Lift the cover to remove it from the system.
12 Removing and installing components