HP EliteDesk 800 Hardware Reference Manual page 18

7. Slide the access panel forward, and lift it off the computer (2).
WARNING!
to cool before you touch them.
NOTE:
8. Disconnect the fan cable (1) from the system board.
9. Remove the three screws (2) securing the DGPU to the system board.
12 Chapter 3 Hardware upgrades
To reduce risk of personal injury from hot surfaces, allow the internal system components
Your computer model may look slightly different from the illustrations in this section.