My dad ordered a set of aftermarket rotors, and when he tried to put them on, he ran into trouble getting the Brembo calipers off. He tried one bolt, and couldn't get it off. He installed aftermarket rotors on his G8, but it didn't have Brembo calipers.

I've looked everywhere online for him and couldn't find anything of help (that usually happens to me, no matter what I look up for any car). This is one of 2 things, performance-wise, left on his Camaro. Any help would be greatly appreciated.

EDIT: He got it.