Lift the side of the logic board opposite the ports out of the upper case.

Rotate the logic board away from the upper case until the ports clear the lip molded in the upper case.

Pull the logic board and MagSafe board away from the edge of the upper case as one piece.

The MagSafe board may get accidentally disconnected during this process. As a precaution, be sure the MagSafe board connector is securely seated in its socket before lowering the logic board back into the upper case.

Before lowering the logic board back into the upper case, be sure the left speaker and microphone cables are seated in their channels cut into the upper case (as seen in the third picture).