Use a T5 Torx driver to remove the ten screws securing the logic board to the frame:

Six 3.8 mm screws

Four 4.6 mm screws

Use a 4 mm Hex driver to remove the two 6 mm screws securing the logic board to the frame.

Use a T6 Torx driver to remove the two 6 mm screws securing the heat sink to the logic board and frame.