If your microwave door is cracked or the latch is broken, you may be able to replace it instead of purchasing a new microwave. Check the manufacturer's website to find out how to order a replacement door that is compatible with your specific make and model. Your owner's manual may also list a part number, which you can use as a reference when looking for a new microwave door.
Unplug the microwave and set it on a table or workbench. If you have a built-in microwave, you may have to remove some mounting screws or retention clips to get the microwave out of the support bracket. Open the door and take out the glass tray.
Pry off a corner of the plastic panel on the inside of the door with a screwdriver or butter knife. Once it is loose, work the screwdriver or knife all the way around the glass and remove the panel.
Ask someone to hold the microwave door as you disconnect it from the hinges. Depending on the design of your microwave door, you may have to remove a set of screws or slide a pin out of the hinge to release the door. Remove and discard the old door.
Have your assistant hold the replacement door up to the hinges. Attach the door to the hinges by reversing the previous step. Snap the plastic inner panel into place around the glass. Move the microwave back to its original location. Insert and tighten the necessary mounting screws if you are working on a built-in microwave. Set the glass tray back inside the microwave and close the door.