Turn off the electrical power to your dishwasher from the kitchen circuit breaker.
Open the dishwasher door and then remove the bottom and top racks from inside the dishwasher.
Remove the lower spray arm located in the bottom center of the dishwasher. In most dishwashers your can turn the spray arm counter-clockwise and lift it out, and on some models you may need to remove screws that hold it in place.
Remove the screws from the soil accumulator part, located directly below where the spray arm was.
Remove the screw from the sump insert located over the sump pump assembly.
Lift up and remove the entire sump insert. Clean out any debris caught in the insert with warm, running water. Clean with dishsoap and replace.