The dog ears should have some tabs, that lay against the body. The covers will "capture" the tabs, when the mounting screws go back in. I put a small piece of adhesive-backed felt on the body side of the tab, just to provide a little cushion. That's it, unless you need to shim, in which case, you'd place the tabs on top of the shim.
I went from chrome to cream, then black on my Casino. Really changes the look, kinda like a woman changing her hair color.....