BFH, or, Big, ummm, Hammer. Seriously. I wailed on mine with a 22 oz. framing hammer and they wouldn't come off. So I went and got my 4 lb engineer's hammer, gave them a moderate whack and they popped right off. Sounds like you probably have a pretty good groove worn into the drums.

Jason

BTW, if you have a HD rear axle, such as the Sterling 10.25, your GVWR on the door sticker will be around 8800 lbs. Otherwise, it will be something like 7500 lbs. For the Sterling full-float axle, you don't have to take apart the axle to get the drums off.