See if
Crutchfield might be able to help you in taking it out. Obviously you're not buying anything from them, but mebbe they have removal instructions somewhere on their site, or a kind-hearted representative of theirs might take pity on you and send or e-mail them to you.
I know the last part of that is a stretch, but you never know, it COULD happen!
Otherwise, perhaps pick up a Haynes or Chilton manual - mebbe they describe how to do it, too....removal with something other than a hammer, that is
