Turn off the water to the sink. When installing a garbage disposal, be mindful of safety. If you have an existing outlet with which to power the disposal already, you may want to deactivate power to that circuit now as well. If you do not have an existing outlet, see Step 6. Remove the existing waste (drain) pipe (or pipes, if you have a two-bowl sink)that connects at the sink strainer and at the threaded fitting at the wall or floor (the stub out). Save the piping for possible reuse if it is plastic with compression, or “threaded-type” fittings. If the pipe is welded or metal, toss it. Unscrew fittings by hand or with groove-joint pliers. Use a hacksaw to cut a welded pipe.
Before starting, be sure to read the manufacturer’s instructions carefully. This is a general guide for installing a garbage disposal; your particular model’s installation may require specific steps.
Be sure you have enough room underneath your sink to install the disposal.
Place a pan or bucket under the drain trap to catch any water that may spill as you remove the drain plug, if there is one, or disconnect the trap.