If you are reusing the LCD, it is not necessary to peel the ambient light sensor off the back face of the LCD.

Use the edge of a plastic opening tool to carefully pry the ambient light sensor board off the adhesive securing it to the display frame.

Once you've gained enough clearance, peel the ambient light sensor off the LCD.

Be careful not to crease the ambient light sensor below its top section, as the portion with adhesive applied may break off.

If necessary, attach the plastic view window to your new ambient light sensor before installation.