Dell Precision 7920 Tower Owner's Manual page 26

4. Install the right side cover
5. Flip the system back with the system cover facing up where the release latch is available.
6. Remove the following components :
a) side cover
b) air shroud
c) PCIe card holder
7. To remove the intrusion switch module:
a) Pull the bottom intrusion switch cable up toward the chassis [1].
b) Press the tab to disconnect the intrusion switch cable from the system board [2].
c) Unroute the intrusion switch cables from the clip on the chassis [3].
d) Remove the screw on the intrusion module [4].
e) Lift the intrusion module from the front system fan assembly [5].
26 Removing and installing components