Chosen Solution

How do I replace the splash guard on my disposal unit without having to dismantle the entire unit?

You have to detach it from the sink. Disconnect the discharge hose, unplug the power cord, and work on it outside the sink. It’s a god idea to preorder the splash guard first, so the sink is not out of commission for long.

If you are talking about the rubber piece right at the top of the garbage disposal, you simply take a flat head screwdriver or needle nose pliers and pull it out and insert the new one.