Turn off the home's water supply at its main shutoff. If you can't find the shutoff, turn off the water at the main, located near the street at the front of the house. Lift the cover, and use the water key to turn the rectangular knob counterclockwise, or all the way to the left.
Check inside the house to make sure that the water is off. Turn on the kitchen faucet's hot and cold water handles to release pressure from the lines.
Find the hot-water shutoff valve under the sink. The hot-water valve usually is located to the left of the sink; the cold-water valve is on the right. The dishwasher must connect to the hot-water valve.
Loosen the retaining nut on the hot-water line with a pair of pliers so that you can remove the line from the shut-off valve. Loosen the retaining nut that holds the shutoff valve to the hot water pipe coming out of the wall, using the adjustable wrench. Turn the nut counterclockwise to loosen it so that you can remove the valve.
Take the valve with you to the home improvement store. Purchase a new valve that is the same size, but has two waterline connections instead of one. The second connection is for the dishwasher.
Wrap a strip of plumber's tape around the threads on the hot-water pipe under the sink. Connect the new shutoff valve to the pipe with the wrench, making sure one of the waterline inlets is be facing up and the other is facing to the right. Reconnect the hot-water line from the sink to the top inlet on the shutoff valve.
Connecting the Dishwasher
Lay the dishwasher on its back. Connect the dishwasher waterline to the inlet valve, a brass connection located near the front of the dishwasher. Tighten the retaining nut with the pliers.
Slide a clamp over the end of the drain hose that connects to the dishwasher. Slide the hose onto the drain outlet pipe on the bottom of the dishwasher, located near the center. Slide the clamp so it covers the drain hose and the drain-hose pipe. Tighten the clamp screw with the Phillips screwdriver.
Set the dishwasher upright. Remove the cover to the junction box on the back of the dishwasher. Connect the black wire on the cord to the black wire on the dishwasher. Place a wire connector over the ends of the wires and twist it to join the wires securely. Connect the two white wires in the same way. Connect the green wire to the green or copper wire on the dishwasher using the same method. Put the junction box cover back in place.
Cut three 1 1/2-inch holes in the side, and toward the back, of the sink cabinet, using the 1 1/2-inch hole saw and the variable-speed drill. The holes will allow the dishwasher lines to be threaded through to the hot water shutoff valve, the garbage disposal, and the electrical outlet.
Slide the dishwasher carefully backward. Leave enough room to reach behind it so you can slide the lines and the electrical cord through the holes you cut in the cabinet.
Connect the dishwasher's water inlet line to the hot-water shutoff valve. Tighten the retaining nut with the pliers.
Plug the electrical cord into the outlet under the sink that the garbage disposal is plugged into.
Punch out the end of the drain tube protruding outward off the garbage disposal, using the screwdriver and hammer. This tube will be close to the top of the disposal. Slide a clamp over the end of the dishwasher drain hose, then slide the drain hose onto the garbage disposal drain tube. Place the clamp so that it is on the drain hose and the tube. Tighten the clamp with the Phillips screwdriver.
Drive a screw partially into the back of the cabinet, making sure that it is higher than the drain tube on the dishwasher. Wrap one end of the 4-inch wire around the screw. Bend the other end into a hook shape. Drape dishwasher drain hose over the hook.
Turn the water back on. Test the dishwasher to make sure that it is functioning properly.