HP ProDesk 400 G4 SFF Hardware Reference Manual page 28

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.
9. Store the removed card in anti-static packaging.
10. If you are not installing a new expansion card, install an expansion slot cover to close the open slot.
CAUTION:
cover for proper cooling of internal components during operation.
11. To install a new expansion card, hold the card just above the expansion socket on the system board and
then move the card toward the rear of the chassis (1) so that the bracket on the card is aligned with the
open slot on the rear of the chassis. Press the card straight down into the expansion socket on the
system board (2).
NOTE:
properly in the expansion card socket.
20 Chapter 2 Hardware upgrades
After removing an expansion card, you must replace it with a new card or expansion slot
When installing an expansion card, press firmly on the card so that the whole connector seats