How do you remove seat belt shoulder bracket in a car?

Unlike most vehicles where the seat belt is attached and hangs on the pillar in between the two doors of the car, my seatbelt is attached on top of my seat. Its only like this for the front two seats. I just bought some seat covers and I need to remove this seatbelt bracket to put on the seat cover and then I will reinstall it. There is one screw that I took out but it still doesnt move, any ideas? (I have a chevy trailblazer 06) thanks for the help.