Using the flat side of a file to turn the nut, unscrew the suction port nut from the pump body. If you have a metal suction screen, this will be difficult. Late model machines have the motor mounted right under the pump, but the parts are virtually the same. Unfortunately there usually isn’t a quick fix to this type of fault and a replacement part will be required.
You usually need to remove these machines from under the kitchen counter to remove the pump and motor unit. This is the impeller with the tall center hub, and it can be difficult to keep the shims in place while you lower the impeller over the shaft. Usually the other outlet beneath the sink is for the garbage disposal, which is wired through a switch near the sink. The wash pump cover and separator are somewhat different, and are removed with a torx bit. Two different kinds of macerators were used; a blade-type, and a wire-type. If you have a blade-type, hold the motor fan blades and unscrew the macerator from the impeller. If you have a wire-type, there is no need to remove it yet.
Remove the securing screws from inside the tub, then remove the collar and lift the pump and motor out as a unit. Most built-in models are also fastened to the countertop by two screws at the front of the machine; open the door to access these screws. Luckily it’s a very cheap part if you need to replace it, the only real difficulty is getting access to it as you’ll find it underneath the dishwasher.