Dell XPS 8920 Service Manual page 64

3. In a non-adjacent sequence as indicated in the figure below, loosen the captive screws that secure the heat-sink assembly to the
system board.
4. Lift the heat-sink assembly off the system board.
Figure 32. Removing the captive screws
a. heat-sink assembly
b. captive screws (4)
c. system board
5. Disconnect the blower cable from the system board.
For more information, see
64 Removing blower and heat-sink assembly
"System-board components".