HP Compaq 6000 Pro SFF Hardware Reference Manual page 29

c. If you are removing a PCI Express x16 card, pull the retention arm on the back of the expansion
socket away from the card and carefully rock the card back and forth until the connectors pull
free from the socket. Pull the expansion card straight up from the socket then away from the
inside of the chassis to release it from the chassis frame. Be sure not to scrape the card against
the other components.
Figure 2-14
10. Store the removed card in anti-static packaging.
11. If you are not installing a new expansion card, install an expansion slot cover to close the open
slot.
CAUTION:
slot cover for proper cooling of internal components during operation.
ENWW
Removing a PCI Express x16 Expansion Card
After removing an expansion card, you must replace it with a new card or expansion
Removing or Installing an Expansion Card 23