To remove the system fan, flip the laptop over and remove the 6 screws from the base cover. Find and loosen the 2 screws at the back of the cover and gently pry the cover away from the hinges. Lift the base cover, locate the system fan, and unplug the cable connecting it to the motherboard. Remove the two screws securing the fan and lift it up and away from the system.
To reinstall the fan, screw it back into place and reconnect the cable, securing it to the motherboard. Secure the base cover with the screws.