Dell OptiPlex 9010 (Mid 2012) - Manual (Page 26)

4. Pry and remove the system fan away from the four grommets securing it to the back of the computer.
Installing the System Fan
1. Place the chassis fan in the chassis.
2. Pass the four grommets through the chassis and slide outward along the groove to secure in place.
3. Connect the fan cable to the system board.
4. Install the cover.
5. Follow the procedures in After Working Inside Your Computer .
Removing the Thermal Sensor
1. Follow the procedures in Before Working Inside Your Computer .
2. Remove the cover.
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