HP zx5000 - Manual (Page 184)

Removal and Replacement Procedures
Maintenance and Service Guide 5–77
2. Turn the system board right-side up with the rear panel away
from you.
3. Remove the PM2.5×5.0 screw 1 and the 4 PM2.5×6.0
screws 2 that secure the fan assembly and processor bracket
to the system board.
4. Remove the processor bracket 3.
Removing the Fan Assembly Screws