Need info. regarding Chevy dually brakes

I have a 1999 Chevy 3500 LS Crew Cab 1 ton dually. Could someone experienced with the chevy dually tell me how to get the rear brake drums off? I got as far as removing both wheels on one side. I'm trying to replace the brake shoes. Do I remove the bolts off the axle hub? Is the axle hub one piece with the drum or are they two separate items? If the axle hub is removed, will the drum come off without any further dismantling? What should I expect if I have to remove the axle hub? Any warnings? Thanks in advance.