Dell Precision 7920 Owner's Manual page 19

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].
Removing and installing components 19