undo the heater nut till level with the end of thread ,now give the end a sharp tap INWARDS the threaded part will move in wards releasing the inner plate,now remove the wires( note positions) pull /ease out the heater
new heater smear of washing up liquid around rubber to make it slip inward,when in do not over tighten nut as WILL SPLIT THE DRUM CASE, refit the wires pour some water in through the door and test for LEAKAGE. reassemble machine
howtomendit.com for free repair help, information and advice.
Try fixfault.com to fix washing machines.