on the p12 they should be on each side of the back of the heelpeice, and either holding the break on such as on a tyrolia, or infront of the break. (if forget specifically)
my importantly take it to a shop. cause if you cant find the screws from looking at the binding i dont think you should be taking it off.
also if you are mounting them on another ski at a shop, they should remove the bindings from said ski for free.
gear talk next time.