The lower part of the metal retaining clip gets pushed to the right, to release the top part to the left, probably with a good helping of WD40. It’s usually the plastic elbow of the inlet pipe, the right one, that splits and leaks. Normally, the whole assembly with hoses has to be replaced, at an extortionate cost. The drawing shows the original at top, and the compatible, cheaper, later replacement at bottom. http://i132.photobucket.com/albums/q23/Clogzz/th_Heater_hoses.jpg http://i132.photobucket.com/albums/q23/Clogzz/th_Heater_inlets.jpg http://i132.photobucket.com/albums/q23/Clogzz/th_Heater_and_hoses.jpg