HP ProDesk 400 G4 Maintenance And Service Manual page 38

3. Tilt the fan up using the front tab and leave it in the up position.
NOTE:
4. Locate the memory module locations (1) and (2) on the system board.
5. To remove a memory module, press outward on the two latches on each side of the memory module (1),
and then pull the memory module (2) out of the slot.
The computer automatically recognizes the new memory when you turn on the computer.
30 Chapter 4 Removal and replacement procedures
It is not necessary to fully remove the fan to remove or install a memory module.