Steps:
- Use the manufacturer’s template to mark cutout lines onto the wall.
- Cut through the drywall using an oscillating multi-tool.
- Pull the insulation from within the hole.
- If there’s a wall stud in the way, enlarge the hole in the drywall and cut out the stud with the oscillating multi-tool.
- Reframe the opening using 2x4s; install a bottom plate, header, jack studs and blocking. Secure the new framing to the old framing with 3-inch screws.
- Fill in voids within the new framing with fiberglass insulation.
- Screw a ½-inch plywood panel over the new framing.
- Screw the oven’s mounting bracket to the plywood panel and framing.
- Drill holes through the house wall from the inside.
- From outside, cut through the siding using a right-angle grinder or oscillating multi-tool.
- Cut through the plywood house sheathing using a reciprocating saw.
- Spray expanding foam insulation around the inside of the wall hole.
- Set microwave oven onto the bracket, then screw down through the upper cabinet and into the top of the microwave.
- Apply silicone sealant around flange of the vent hood, then slide it into the hole and screw it to the house siding.