How do you remove the bolt to the housing that holds the rear brake shoes on a 2000 chevy silverado 1500 z-71.

I have changed brakes on previous vehicles and the bolt came right out. This one will loosen but it only goes so far and just spins. The threads are still intact.|||Is it a captured bolt, meaning that it was not designed to come out of the housing? You loosen the bolts and then push the caliper in and lift it off the rotor. Then to remove the rotor to have it turned you have to take the mounting bracket off the truck with two bolts that tend to be extremely tight.