Some may have screws under all the dirt, BUT, getting them out is another thing. I've had to take a chisel and catch an edge on them to get out. Easiest just to pull hub and drum one piece, then they can turn on machine if needed. They don't have tapers big enough for just the drum where I go, they need the hub for centering. A brake shop I get parts from, quite commercial has truck outfits leave the wheel and all on the drum/hub and they mount whole thing in machine to turn. Don't know the advanatage to that, but bet they have plenty jacks and roller rigs to do it!
