Drill a hole in the center of the nub and insert a screw, making sure it's snug. Put a wide putty knife on the face of the cabinet and use the claw of a hammer to lift the nub out by the screw- it should come out. If it doesn't, drill a row of small holes across the center of the nub and make sure to avoid drilling into the face. insert the flat blade of a screwdriver into the slot and pry gently- one side should come out or, you may be able to repeat the previous procedure.
