Remove the power cord from the electrical outlet and move your microwave onto a workbench or sturdy table. For cabinet-mounted microwaves, pry off the decorative grills or front panels and remove the mounting screws. You should then be able to slide the microwave out of its mounting bracket.
Open the microwave door and remove the glass tray. Use a flathead screwdriver or putty knife to pry off the plastic cover on the inside of the door. Work around the edge of the glass until the cover slips free.
Remove the door by pulling the mounting pins out of the hinges at the top and bottom. You may need an assistant to steady the door so you can have both hands free to work with the pins.