Installing a New Garbage Disposal

First, get all tools and have them within arm's reach. Once you've got all the necessary equipment, disconnect the waste assembly and take it off of the sink flange and to the trap.  There is likely to be some water and debris inside that will pour out when you do this, so place a bucket or large pan beneath it to catch the waste.  Use towels to clean up anything the bucket misses.  After you get the waste lines out of your way, remove from the disposal the entire mounting assembly.  Then in the sink hole, you'll install your new flange. As you do, you should apply some plumber's putty around the flange and then drop it into its place.

Next, you'll connect the sink flange to the upper mount assembly; hold the flange in place with something heavy like a telephone book.  Place the gasket according to the instructions, and then slip the mount ring over your flange.  Now slide the snap-ring on your flange; it should pop into the flange's groove easily. After this, find the three mounting screws and tighten them.  You want the screws tight enough that the assembly is secured tightly against the sink.

Attach the tube from the disposal to the mount assembly.  If there is any hardened waste on the P-Trap, clean it before you go further. Now, in order to prepare the drain connection to the dishwasher, knock out a drain plug from the nipple on the dish-washer, then attach the drain's hose coming from the dishwasher.

Next, situate the garbage disposal beneath the mount assembly until the mount tabs are able to slide over the mount tracks.  Lift up on the disposal, then place its top into the mount assembly.  Turn the lower mount ring, and keep turning until the three mount tabs lock over the ridges in the ring.  Now tighten the ring with a screwdriver or wrench.

Turn the garbage disposal until the discharge tube is completely aligned with your drain trap.  For a double-bowl sink, you have to replumb your waste-line to connect to the garbage disposal.  Hopefully, all you'll need at this point will be an extension tube.  Otherwise, you may have to replace the whole assembly.

You're almost finished; now you just need to hook up the power to the garbage disposal.  You can run a line to it or, for something more permanent, hire an electrician to run power directly into your sink cabinet.

Installing a garbage disposal is not that difficult, although it can be somewhat messy.  But most people agree that a day of work and mess is worth it for the year's of convenience the disposal will provide.