When installing an "over range" Samsung Microwave you must have between 30 and 36 inches of space between the cabinets over your stove. Without this space, your microwave oven will not bolt into place. Samsung microwaves can vent to the outside like your existing range hood does, or it can vent back into the room. Venting into the room is easier if you do not already have an exhaust port installed into the wall.
Remove the two screws that secure the mounting plate to the back of the microwave oven. You will use the mounting plate as a template for drilling your mounting holes.
Locate the center of the studs on the wall where you want to mount the microwave. Use a stud finder to locate the studs. As a note, you must mount the microwave to at least one stud. Mark each stud with a pencil.
Place a level across the bottom of the cabinet to ensure the cabinet is level. If there is no rear overhang, install a wood strip on the bottom of the cabinet so the microwave stays level.
Measure across the width of your opening and scribe a line in the center with a pencil.
Place the mounting bracket against the wall and line up the center line on the bracket with the line on the wall. Make sure the top of the bracket touches the bottom of the cabinet overhang against the back wall.
Mark each mounting hole for the bracket onto the wall. Make sure the mounting holes connect with at least one stud. Place the mounting bracket off to the side and then drill pilot holes in all the locations you marked.
Secure the mounting plate to the wall with wood screws for all holes located in a stud and toggle bolts for all screws secured only to drywall.
Place the top cabinet template onto the bottom of the cabinet. Drill holes where the template indicates. This includes the hole for the power cord. Use a hole saw for drilling that hole.
Thread the Samsung microwave oven cord through the hole in the top of the cabinet and secure the back bottom edge of the microwave into the lip on the mounting bracket. Slide the oven back against the wall.
Secure the self-aligning screws into the top of the microwave thought the top cabinet.
Install the carbon filters into the front vent of the microwave for recirculation of exhaust. This prevents the need for outside ventilation.