Dell 23.8" OptiPlex 7410 All-in-One Desktop Computer (Gray) - Manual (Page 87)

The following image(s) indicate the location of the heat sink and provides a visual representation of the removal procedure.
Steps
1. In reverse sequential order (5>4>3>2>1) loosen the five captive screws that secure the heat sink to the system board and
display-assembly base.
2. Lift the heat sink off the display assembly base.
Installing the heat sink
Prerequisites
If you are replacing a component, remove the existing component before performing the installation process.
About this task
NOTE: If either the processor or the fan and heat sink is replaced, use the thermal grease provided in the kit to ensure that
thermal conductivity is achieved.
The following image(s) indicate the location of the heat sink and provides a visual representation of the installation procedure.
Removing and installing Field Replaceable Units (FRUs) 87