Couple of ways really...you could take off the sump hose in the bottom of the tub & fish it out from there, or remove the heater element & do the same. However before you go that far have a real good look around the inside of the drum for anything protruding slightly (like a bra wire). You might be lucky & fish it out without dismantling. Otherwise it could be a coin or something else trapped between the drum & tub. Whatever it is it needs to come out before it can damage the heater element, or at worst wreck the tub.
Mike, October 2009