Step 25
Disconnect the DC-In cable from the logic board.
Step 26
Deroute the cable from around the optical drive, removing tape as necessary, and angle the DC-In board out of its compartment.
Step 27 — Upper Case
Remove the following 11 screws from the bottom of the computer:
Three 3 mm Phillips around the battery compartment.
Three 4.5 mm Phillips along the optical drive bezel. (a magnetic screwdriver may help to lift these screws out)
One 12 mm Phillips in the lower right corner.
Four 14.5 mm Phillips.