Remove the old kitchen cabinet that is located on top of the stove.
Install a wall socket where your microwave oven will be connected for power. You can do this yourself or hire an electrician to do this.
Add new cabinets that have been made to measure or bought ready made with correct size for the right height. Apply a stain to match the existing cabinets' finish.
Install the new microwave oven by drilling the braces on to the wall studs using drill and screw driver.
Test for stability and usability. Try the microwave cooker and vent.