Removing the Old Machine First, shut off the water and power to the machine. The dishwasher should have its own shutoff valve in the cabinet under the kitchen sink. But installers like Fred Schlott, an assistant manager at The Home Depot in Port Chester, New York, and the pro doing the installation seen here, cautions against trusting this valve completely. After sitting in the open position for years, an inexpensive valve can spring a leak when disturbed, or internal corrosion may make it nearly impossible to close. If that's the case, turn off the water for the house and replace the dishwasher shutoff. As for the power, because built-in dishwashers often are hard-wired (not a "pigtail" that's plugged into a receptacle), you should turn off the power at the main electrical panel or, if you have one, at the cutoff switch near the appliance. Your dishwasher is connected to a hot-water supply line, a discharge line and an electrical feed, all of which must be disconnected. You'll find the supply line and electrical connections in the cramped space between the bottom of the dishwasher tub and the floor. To get at them, remove the access panel at the bottom of the dishwasher, which is held in place with a few sheet-metal screws. The water-supply line ends at an elbow near the left front corner of the machine. Use pliers or an open-end box wrench to loosen the compression fitting. A shallow dish or a rag will catch the small amount of water left in the line. Inside a metal junction box you'll find a pair of wire nuts connecting black and white wires from the power feed to the machine. A bare ground wire should be connected to the box with a green screw. Disconnect them all; save the wire nuts and the box connector for the new power feed. One thing to watch for: Dishwasher installations in new construction are required to have a dedicated 20-amp circuit with 12-ga. wire. If the cable is undersize or the equipment ground is missing, you may want to hire an electrician to upgrade the circuit. You also need to disconnect the dishwasher drain line from the sink drain or garbage disposer. It's usually held in place with a hose clamp. Replace this discharge line when you put in your new dishwasher (you'll get one with the machine). With plumbing and wiring lines disconnected, all that's left are two screws attaching the dishwasher to the underside of the counter. The two metal clips holding the machine in place are visible with the door open. Once these have been removed, ease the dishwasher out of its opening. It will be easier to remove if one person feeds the drain line through the hole in the side of the sink cabinet as a second person wiggles the old machine out. It can be a tight squeeze. If you find water damage to flooring in the dishwasher cavity caused by a leak in the tub, supply line or discharge hose, repair the flooring before installing the new unit.