There should be some countersunk screws holding the drum to the hub. Providing that the screws and drums are not too rusted up the drums should slide off. You may also have to back off on the brake adjuster.
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