HP Compaq NC4400 Maintenance And Service Manual page 108

Removal and Replacement Procedures
6. Lift the right side of the heat sink 1 to disengage it from the
processor.
7. Slide the heat sink up and to the right 2 to remove it.
✎
Due to the adhesive quality of the thermal paste located
between the heat sink and processor, it may be necessary to
move the heat sink from side to side to detach the heat sink
from the processor.
Removing the Heat Sink
5–26 Maintenance and Service Guide