oldfordisbetter

my gt doesnt have a spoiler on it. i my brother has a wing from a capri of same year. dry fit it fits and looks good. but it has the 3rd brake light in there. anyways it has these bolts comming out undernieth it. how would i mount it to my hatch? if i drilled holes in hatch i would also have to cut open underside of hatch to be able to put washers and locknuts there. is that the right way to do it or is there another?