beat it with a hammer. that usually will work quite well.
seriously though, just angle it in, and then seriouly apply pressure on the clips, working from the outside in.
<span style='color:gray'><span style='font-family:Courier'>1995 e36 3 Series RIP
1999 e46 3 Series BURN IN HELL
2000 MR-S Roadster= Current</span></span>