Dell XPS 8500 Owner's Manual page 105

5 When the processor is fully seated in the socket, close the processor cover.
6 Pivot the release lever down and place it under the tab on the processor
cover.
CAUTION:
Ensure that the processor cover notch is positioned underneath the
alignment post.
1 alignment post
3
release lever
5 processor cover notch
4
5
2 processor cover
4 processor
3
2
1
Processor
105