Remove all parts of the disposer kit from the box, and organize the contents. Remove the P-trap and existing drain basket assembly carefully from the sink (Images 1 and 2). Place a large pan below the sink to catch water that might spill when you disconnect the drain, and keep a towel close by to clean up spills.
Locate the flange gasket. Some kits will come with a rubber gasket, but using plumber’s putty will give your seal a longer life. Roll the putty into a snake shape approximately 3/8” in diameter and long enough to wrap around the gasket under the flange (Image 1). Press the putty evenly around the underside of the flange using your fingers as you would along the edge of a pie crust (Image 2).
Insert the flange on the top side of the sink, and attach the fastening system on the underside (Image 1). It is helpful to apply pressure on the flange from above using a second set of hands or a heavy object. This will keep the flange in place while attaching the fastening system below. Make sure the plumber’s putty is visibly oozing beyond the edge of the flange all around (Image 2). Remove the excess putty with a rag once a complete seal has formed.
If you plan to drain your automatic dishwasher through your disposer, locate the breakout plate inside the inlet port (Image 1). Remove it by gently punching it with a screwdriver and hammer (Image 2). If you will not use your unit to drain a dishwasher, leave the breakout plate intact.
Some disposer units do not come with a power cord attached. If this is the case, remove the plate with a screwdriver to access the electrical wiring (Image 1). Be sure to purchase a wiring kit with the proper power rating and hardware for your disposer unit (Images 2 and 3). When you connect the wiring harness to the disposer, ensure the cord is long enough to reach the receptacle without stretching the cord.
Align the rubber seal ring on the top of the disposer with the flange beneath the sink. Press it into place, and loosely secure it by rotating the lower mounting ring onto the ramp tabs of the upper mounting ring. Rotate disposer unit as needed to align drain assembly.
The disposer unit is heavy and can be awkward to maneuver beneath the sink. Use a large bowl or other sturdy object to prop up the unit as you position it.
Test for water tightness by plugging the drain with the stopper and filling the sink with an inch of water. Check for leaks under the sink to confirm that your plumber’s putty is making a good seal. Remove the drain stopper, and allow the drain and P-trap to fill with water. Check for leaks and tighten as necessary. Plug unit into a GFCI-protected receptacle, and organize cords as desired.