Disconnect the upper fan connector from the motherboard.
Remove the four spring loaded screws holding the heat sink assembly to the motherboard.
When reassembling, ensure that all the screws are equally tightened: thread all screws one turn, then add one turn to each screw in the following order: top left, bottom right, bottom left, top right. Repeat this order until the assembly is firmly seated.
Slide the heat sink assembly including the upper fan out by pulling it down and left simultaneously.
When reinstalling the heat sink, ensure it is thoroughly cleaned and the thermal paste (or pads) are replaced to ensure proper thermal contact with the devices on the logic board.
Remove screws from the battery area, noting the following:
These screws are on oversize clearing holes, but hold other components on the keyboard. It is not recommended to remove them yet.
Two screws secure the optical drive: one in the battery compartment and one in the RAM compartment.
With the screws removed, PUSH the optical drive out through the opening at the BLUE arrow. You will need to remove the drive to access two more screws at the edge of the frame in the opening of the optical drive.