Turn off the power supply for the dishwasher. Locate the main circuit breaker in your house and identify which breaker controls the dishwasher. In modern homes, the dishwasher should be installed on its own circuit. Flip the switch that controls the dishwasher to the "off" setting.
Turn off the water supply for the dishwasher. The supply valve is usually located underneath the nearest sink. Look for a dual supply valve where the dishwasher supply line is connected, with the second hose leading up to the faucet above. Grab the knob and rotate it clockwise with your hand until it stops.
Look for the screws on the side of the kick panel just beneath the dishwasher door. If you cannot see them or reach them with a screwdriver, the dishwasher will have to be moved out of position so the screws can be accessed. Loosen the screws in the brackets holding the dishwasher in place underneath the cabinet. Gently edge the dishwasher forward so you can access the kick panel screws.
Loosen the kick panel screws on the sides of the panel. Some kick panels may also have screws on the top. In order to reach these, open the dishwasher door so you can remove the screws from above. Pull the kick panel out of position.
Look for the dishwasher inlet valve. The easiest way to identify the valve is by looking for the water supply hose connected to the outside.
Place a towel on the floor underneath the valve. Use a wrench to loosen the coupling connecting the water supply line to the inlet valve. Wipe up any water that spills out with the towel.
Make a note of where the wires or the wiring harness connects to the inlet valve for when you're replacing it. Carefully pull the wires or harness out of the inlet valve.
Loosen the screws holding the inlet valve body in place on the underside of the cabinet.
Use a pair of needle-nose pliers to pull the screen out of the inlet valve.