Does anyone know how to loosen the big plastic nuts that hold the u bend in place, i would think they havent been off in at least 15 years and they wont budge . Is there a tool designed for this or what do people use . The kitchen sink one i can undo by hand but the laundry one is stuck fast and i have already flooded the laundry once so the wife is not keen for me to do it again . Help.