Turn off the circuit breaker to the Whirlpool dishwasher. Open the dishwasher door and lay a towel in the bottom of the lower dish rack. The towel helps prevent accidentally dropping screws into the pump filter.
Grab the sides of the dishwasher and pull it out of the cabinet to expose six inches of the sides. This gives you access to the outside of the Whirlpool dishwasher without disconnecting any lines.
Insert the end of the side mounting bracket with the two hooks into the slot on the side of the dishwasher. The brackets will only go into the slot one way. Press the bracket down once you insert it fully into the slot to engage the hooks. Repeat for the opposite side of the dishwasher.
Push the dishwasher back into the cabinet. Insert a mounting screw through the hole on the exposed end of the side mounting bracket. Secure the screw into the cabinet frame with a Phillips screwdriver. Repeat for the opposite side of the dishwasher.
Take the towel out of the dishwasher, and close the dishwasher door. Turn the circuit breaker back on to power the Whirlpool dishwasher.