Purchase a microwave that matches the dimensions of the space over your oven range. Use a tape measure to measure the space.
Lay out the microwave components. You will have the wall mount, screws and range mounting studs. A wall diagram and cabinet diagram will also be included.
Tape the wall diagram to the wall where you intend to mount the microwave. Tape the cabinet diagram under the cabinet, where the top of the microwave will attach.
Place the metal wall mount over the marked area on the wall diagram.
Attach the screws to the holes in the wall mount and tighten to secure them.
Drill and saw through the marked areas on the cabinet diagram to form the vent hole, power cable hole and mounting holes. Use a hand saw to cut out the marked vent area and use a 1 1/2-inch drill bit to cut the power cable hole. Use a 1/2-inch bit for the mounting holes.
Lift up the microwave with the help of an assistant and place the bottom rear corners over the metal mount. Place the microwave flush against the wall.
Slide the microwave power cable through the cabinet hole. Attach the mounting studs into the holes in the top of the microwave. Tighten the studs to secure the microwave.