dent in roof..how do i get it out?

theres i dent in the roof of my 87 cutlass ciera, and i dont know how to get it out. if i push it up from inside it just pops back down. its kinda big, like 12" around. i was thinkin about putting a sunroof in it, and i think the dent would be a problem. either way, how can i get it out?

Your could take a fiberglass hood scoop or somthing like that off ebay and then just use bondo or somthing to mold it on....just a quick idea.