I have this Shimano Exage hub and 6 speed cassette on it. I want to remove the cassette and soak / clean it for obvious reasons. How is this thing held on? There is no lock ring. Looks like an actual freehub on there so I doubt this is a freewheel. There is a tab on the freehub to whack it off counterclockwise but will that remove the whole freehub?