Unplug the microwave from the wall or socket.
Open the microwave door. Check above the microwave for a grill or hood. Locate the screws holding the grill in place and remove them with a screwdriver. Set the grill aside. Remove the door by lifting up on the hinges.
Insert the edge of a putty knife in between the back of the door and the edge of the plastic insert that runs around the inside of the door. Slowly move the putty knife down the plastic, prying it away from the door as you move around the circumference. Pull the plastic frame off the door.
Pull the door grid out of the microwave oven.