I have a Kitchenaid kudm01tj bl0 dishwasher that we just noticed is full of dirty water at the bottom of the tub. We put it on "drain" and you can hear a faint humming sound under the dishwasher, but no draining. I pulled the hose from the garbage disposal, and it is not clogged. So I called a repair company who I wan't too impressed with. They spent just a few minutes looking at it and assumed that it needs a new drain pump, and quoted $325 to do it.

The pump itself is about $45, but I have no idea if that would fix it, and if you think so, how difficult are those to replace for someone with limited skill? Is there something else I should check before going forward with replacing the pump?

Thank you!