The hub and drum are riveted together as stated above. However, it is possible that the drum may have been changed at some point. Most of us do not re-rivet a new drum to the hub so the drum can come off without removing the hub. It's still probably not possible to get everything apart without removing the hub. Therefore just remove the cap, cotter pin, nut and the hub will come right off.
Fred


1956 3100 Pickup/Red/350/3sp OD/PS/Disc Brakes
1957 Bel Air Sport Coupe/Red/355/TH350/PS/Disc Brakes
2017 Silverado LT Single Cab SB/Black/5.3/6 Speed Trans
1947 Willys CJ2A w/F-Head engine