how exactly do these work? because the black grill peices in the trucks dont come out. so how do you put the billit grills in them?

Cut out the black or you can put it in over it

The one I put on my wifes 2003 had those spring loaded wall anchors. Just push them through the openings in the stock grill and tighten with a screw driver from the front. You don't remove anything to install it.