Carefully insert a small flathead screwdriver or Jimmy in the seam between the metal casing and white plastic top. Use the screwdriver to pry up the white plastic top bezel. Be careful not to damage the soft plastic with your screwdriver.

The top bezel is held on with an adhesive, so it may be necessary to pry up in several different locations to free the part.

To make this job easier, heat up the adhesive with a hairdryer on low heat for a few seconds.