Hello all. I just have a quick question about speakers. I own a 91 740 turbo 4 door. It still has the orginal stock speakers in it and im lookign to replace them. I read up on how to remove them, and i know i must drill out the rivets. But what im not sure about is how to do this. I know i will need a drill, but do i need a special bit or what? Thanks a lot guys.