First as I'm sure you know....put the truck on jackstands and remove the wheel. Depending on the year....you have either slide off rotors...or the rotor is all one piece with the hub. Turn the wheel to the appropriate side that you are working on..this will allow easy access to the caliper bolts. The caliper bolts on a Chevy are an Allen head there are two of them located on the inside rear of the caliper.Remove these bolts...and lift the caliper up off the rotor...you may have to do some prying to get it off. Using a piece of wire or something that will support the weight of the caliper tie it up out of your way....Then using a deadblow hammer tap the rotor around the outside edge...it should pop off the hub...if not spray some PB blaster around the hub..or WD 40..wichever is handy