iFixit

It may be helpful to hold the heat sink in place while removing the right fan.

Lift the right fan up while carefully peeling up the tape which secures the fan to the heat sink.

Remove the right fan from the computer.

Lift up the left side of the logic board and disconnect the multi-colored power cable from the bottom of the board.

The logic board is still attached to the computer by one more cable, so don't lift the logic board too far out of the computer yet.

Grasp the logic board at the left side and at the thin section, and rotate the logic board out of the lower case.

To properly reassemble your MacBook Pro, you'll have to clean off and replace the old thermal compound from the chips on the back of the logic board. Use our Applying Thermal Paste Guide to prepare the processor and heat sink surfaces.

Disconnect the right thermal sensor cable from the bottom of the logic board near the DVI port.

Peel back the orange Kapton tape covering the left thermal sensor.

Use a spudger to pry the left thermal sensor off the heat sink.