How do I clean the drain pump on the WAT28400UC?

First attempt to drain the washer by selecting the Drain program and pressing Start/Pause, then shut off the water tap, switch the appliance off, and unplug it. Remove the service cover, loosen screws and remove the protective film, then use the pull-out drain hose to drain remaining water (up to 5.3 U.S. gallons/20 liters) into a suitable container. Turn the pump cover counterclockwise to remove it, clean the interior of the pump housing of any debris, check that the impeller wheel spins freely, and reinstall the pump cover with the handle in the vertical position. (Page 32)