Remove the following five screws securing the heat sink to the logic board:
Four 6.4 mm T8 Torx screws
One 4.3 mm T10 Torx screw
It may be necessary to hold the socket with a Phillips screwdriver on one side of the board while you unscrew the Torx screw on the other side of the board.
If the two components appear stuck together, carefully pry them apart with the flat end of a spudger, being careful not to disturb any surface-mount components on the logic board.
Make sure to apply a new layer of thermal paste before reattaching the heat sink. Our thermal paste guide makes it easy.
Carefully lift the CPU straight up off its socket.
Be sure your new CPU is properly aligned and seated before clamping it back down. The small gold arrow on the CPU should align with the white arrow printed on the logic board near the CPU socket as seen in the second picture.
Make sure to apply a new layer of thermal paste before reattaching the heat sink. Our thermal paste guide makes it easy.
BTW, what's the most powerful CPU you can upgrade to? 21.5" 2428 logic board no.:820-2641-A. Also, can radeon 6750M be replaced with 6770M or even 6950/6970M?