Apply heat around the perimeter of the lower case to loosen the adhesive that secures the lower case to the chassis.

The plastic should be a bit too warm to touch comfortably, but not hot.

Insert an opening pick in the gap between the lower case and chassis.

After ensuring that the adhesive is warm, slide the pick around the perimeter to sever the adhesive.

As you sever the adhesive, insert additional opening picks at each corner to prevent the adhesive from readhering.

Remove the lower case.