HP ProBook 4520s Notebook PC and HP ProBook 4720s Notebook PC - Maintenance and Service Guide

4.
Clean the thermal material from the surfaces of the heat sink components (1) and the system
board (2) each time the heat sink is removed. Replacement thermal material is included with all
heat sink, system board, and processor spare part kits.
Reverse this procedure to install the heat sink and fan.
82 Chapter 4 Removal and replacement procedures