Disconnect all power flowing to the microwave at the fuse box or breaker.
Unfasten the two screws on the face of the microwave mounting rails and set the screws aside in a safe location.
Slide the microwave unit partially out of the cabinet cavity toward you. Have a partner hold the cantilevered front of the microwave steady while you access the rear of the unit.
Loosen the screw on the mounting box that connects the electrical wire to the power supply. Unscrew or remove each wire from the box. Alternatively, simply pull the three prong plug from the outlet behind the microwave unit, depending on the installation method.
Pull the power cord or conduit and wires attached to the microwave gently from the cabinet.
Slide the microwave forward and out of the cavity in a level plane, working with your partner, so as not to ding the microwave or the surrounding cabinetry.
Set the microwave on a flat, stable surface out of the way where it cannot be damaged. Tape the two mounting screws to the outside of the microwave so they will not be lost.