HP EliteDesk 800 G3 TWR Maintenance And Service Manual page 42

b. If you are removing a PCI Express x1 card, hold the card at each end and carefully rock it back and
forth until the connectors pull free from the socket. Lift the card straight up (1), and then away
from the inside of the chassis (2) to remove it. Be sure not to scrape the card against other
components.
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 (1) and carefully rock the card back and forth until the connectors pull
free from the socket. Lift the card straight up (2), and then away from the inside of the chassis (3)
to remove it. Be sure not to scrape the card against other components.
NOTE:
6. Store the removed card in anti-static packaging.
7. If you are not installing a new expansion card, install an expansion slot cover to close the open slot.
IMPORTANT:
cover for proper cooling of internal components during operation.
32 Chapter 4 Removal and replacement procedures – Microtower (MT) chassis
If the card is full length, you may need to remove the drive cage to remove the card.
After removing an expansion card, you must replace it with a new card or expansion slot