Wood and Formica Countertops
Level out the dishwasher by extending or retracting the leveling legs. Open the dishwasher door and set a level on it. Work with the leveling legs until the level shows the results you want.
Maneuver the dishwasher so the bracket holes line up with the underside of the counter. Don't set them too close to the lip of the counter top -- the bracket holes should be at least 1/2 an inch inside the edge.
Drill pilot holes about 1 inch deep up through the bracket holes and into the counter. Clear away any sawdust that may have fallen down into the open dishwasher.
Fasten the dishwasher to the counter using the screws that came with the dishwasher. Tighten them until the heads are flush with the underside of the counter. Open and close the dishwasher door a few times to ensure that the brackets and screws don't interfere.
Level out the dishwasher by manipulating the leveling legs until the appliance is completely level. Move the dishwasher so that the frame is just inside the cabinetry housing.
Locate the side holes in the dishwasher frame. There may be plastic stoppers covering them; these must be removed and set aside. Confirm that the holes line up with the inside edge of the side cabinets, about 1/2 an inch in from the edge.
Drill pilot holes into the cabinetry on each side of the dishwasher, no deeper than 1 inch.
Insert screws through the bracket hole and secure the dishwasher to the cabinets via the side. Replace the plastic caps to cover the screws.
Open and close the dishwasher door to ensure a smooth seal with no gaps.