HP ProBook 450 G5 Maintenance And Service Manual page 82

5. Lift the heat sink from the system board (2).
NOTE:
components (2) each time you remove the heat sink. All heat sink and processor spare part kits include
thermal material.
Reverse this procedure to install the heat sink assembly.
72 Chapter 6 Removal and replacement procedures for Authorized Service Provider parts
Thoroughly clean thermal material from the surfaces of the heat sink (1) and the system board