Plan two hours to hang the microwave, but it might take longer if venting and wiring are required. Before you begin, move the range if it’s in the way, and install a microwave cabinet. Then follow these steps for how to install a microwave over your range. It’s best to install the ductwork to move the exhaust in the most direct route. Carefully plan a path for your ductwork before beginning, then install a vent above the range. Cut through the drywall with a drywall saw to access the vent.