HP Compaq NX4820 Maintenance And Service Manual page 173

Removal and Replacement Procedures
2. Turn the processor locking screw 1 ¼-turn counterclockwise
until you feel a click.
3. Lift the processor 2 straight up and remove it.
✎
The gold triangle 3 on the processor should be aligned in the
front right corner when you install the processor.
Removing the Processor
Reverse the above procedure to install a processor.
5–60 Maintenance and Service Guide