Is the unit on a pedestal?
Remove the door on the drain cleanout. The tray over the cleanout will have 1 screw in it. Remove the screw and remove the tray. There will be 2 screws holding the pump on. Remove those. Lay the washer on its back(no pedestal) and reach in to the pump. On the floor of the washer, right behind the pump, there is a push tab. Push the tab down and pull the pump backwards. This will allow the pump to move back completely and make it easier for you to reach. If there is a pedestal on the unit you will have to reach in through the back panel to get to the pump.