I want to replace not only the spring but also the cam spindle itself since the interlocking of the lid (also being replaced) is effected by the sloping lugs on the lid and cam spindle arm and BOTH are worn, but it looks like the spindle has a locating spring groove at its lower end, which spring would be inside the main body. Is it possible to replace the spindle from the top just by pulling the old one out and pushing the new one in or does it need to be done by taking the whole dispenser unit to pieces ?