Remove the single silver Phillips screw securing the clear plastic shield over the left ambient light sensor.

Lift the clear plastic shield off the left ambient light sensor.

Use a spudger to pry the left ambient light sensor board out of its housing on the left speaker.

Lift the left ambient light sensor board out of the computer.

During reassembly, you can use a lint-free cloth to remove smudges and fingerprints on the plastic shield if needed.