Step 13 — Left I/O Frame
Disconnect the MagSafe board cable from the logic board.
Step 14
Remove the single Phillips screw securing the left speaker to the lower case.
Lift the left speaker out of its housing and set it to the side.
Step 15
Remove the following 3 screws:
Two 7.5 mm Phillips from either end of the left I/O frame.
One 9 mm Phillips from the middle of the left I/O frame.
Remove the small black plastic spacer at the bottom of the left I/O frame.