I thought that this might be underpowered (my last one almost had double the power, after all), but it has plenty of power to eat through whatever you throw at it. I don't dump EVERYTHING down the drain, but it takes what I give it with no problems. And the last garbage disposal was loud and raucous--yes, raucous. But this one is a pleasure. When you flip the switch, it makes a reassuring hum. It sounds more like a fine piece of machinery than a couple of animals fighting to the death inside my sink (like my old disposer).
Disposers fasten to the sink drain fittings in a number of ways--some use threaded plastic nuts, others large hose clamps--but the mounting-ring assembly shown here is the most common. To remove the disposer, support it from below and rotate the large, 3-tab mounting ring at the top counterclockwise until the unit falls away. Remove the remainder of the drain assembly by loosening the three bolts and prying off the retaining ring. Push the drain out through the sink hole and clear away any old caulk or putty.
A continuous feed model features a switch that is generally mounted on the wall nearby. In rarer cases, an air pressure switch may be mounted on the countertop. These air pressure switches are considered safer than traditional flip switches because they guard against shock by isolating the electrical system away from the sink’s source of water. Batch feed garbage disposals do not require the installation or use of a switch. Safety codes in your community will dictate how far away from the sink the electrical switch must be located.

You’ll need to measure the new discharge tube to make sure it fits into the existing drain assembly. In our installation, the garbage disposer doesn’t use the discharge tube, but connects directly to the drain. If this isn’t a replacement project, you’ll need to tie in a drain assembly to the existing sink drain, which might take reconfiguring the drain. Be sure to reach the manufacturer’s instructions, and check out our Frequently Asked Questions section on this site for more information on how to do this, or visit your local independent home improvement retailer for the products and advice you’ll need for this step of the project.

Loosen the nut securing the rest of the assembly. Just below the sink flange where the drain empties into the garbage disposal you’ll see a circular plastic piece similar in appearance to the mounting ring. Insert the tip of a screwdriver into one of the lugs on this piece and rotate it in a counterclockwise direction. Pull the nut away and set it aside.[9]
If your garbage disposal is making a clicking or rattling sound, there may be some food particles that will not grind up inside. Remove power from disposer, reach into the sink hole with a pair of tongs and remove anything that is still down in the disposer. Test your disposer to be sure the noise is gone. If not continue troubleshooting your disposer issue (see below).

Garbage Disposal Replacement