How to Replace a Built-in Microwave in a Microwave Oven Combo

Open the cupboard above the microwave. There you'll find bolts supporting the microwave -- typically they're held in place with four bolts. Remove the bolts using the ratchet.

Pull the microwave out -- with the assistance of another person -- removing it from the cabinet.

Measure the width, height and depth of the microwave cabinet. These will give you the dimensions needed for your replacement microwave. Built-in microwaves come in a few standard dimensions, making them easy to replace.

Lay out the template for the new microwave in the cupboard where you removed the bolts. The template is packaged with the new built-in microwave, to help you space the bolts properly. Line the template up with the wall at the rear. The spots where the bolts should be installed are marked with dots; poke a hole through the dots with a pencil and mark the spots on the shelf. If you're fortunate, the bolts will be in the same places as the previous microwave -- otherwise you must drill a new set of holes.

Drill holes in the shelf where the spots are marked, if necessary. Use a drill bit that's the same size as the bolts provided by the microwave manufacturer.

Slide the new microwave into the cabinet, with the assistance of another person.

Drop the bolts included with the microwave into the holes that you drilled. Tighten them into the holes in the microwave using the ratchet.