Over-the-range microwaves are conveniently placed and do double duty as range vents. You need a microwave designed especially for the job, as well as a vent to carry away exhaust fumes from the stove. The vent is built into the wall and is easiest to install when you're building or remodeling the kitchen. But if you're good at drywall repair, you can install one in a finished kitchen. You also need a cabinet the microwave hangs from. The cabinet not only provides support but it also contains the wiring for the microwave and may contain part of the venting.
About 2 hours to hang the microwave from the wall and cabinet; longer if venting and wiring is required
Screwdriver, tape measure, stud finder, drywall saw, wire cutters, needle-nose pliers, strippers
Measuring and finding framing, wiring if outlet needed, ability to install vents, if required
Move range, if it's in the way; install microwave cabinet.
Over-the-range microwave; cable; outlet boxes; receptacle; cover, if new outlet needed; vent, if needed