remove the nut till level with end of thread tap the nut inwards this will free the spreader plate that tighten on the other side of the rubber gasket ,remove the heater wires, thermostat wires earth connection,waggle the element from side to side gently pulling at the same time.
On new element smear washing up liquid on the rubber lip to help aid refitting, DO NOT over tighten nut as will split casing.
Test for water soundness,(hint) a kettle of water filled through the drum door will do if o k continue to rebuild machine.
wirecutterman, November 2011