Please forgive me, but what are you talking about?
If you're talking about the front(steering) wheels, you're probably talking about the hub itself that your wheel bolts to? Never heard of a "dual wheel adapter" on the front. If this is the animal you're talkin' about there is no need to remove it. You should be able to remove the dust cap, spindle nut, bearing, and remove the hub/drum all as one assembly. The machine shop should be able to mount the whole unit on their brake lathe. When I worked in the machine shop, I actualy preferred it when people would bring an entire assembly in, a drum by itself is more likely to vibrate and chatter while machining it.
I hope this helps at least a little. Maybe this isn't at all what you're asking about.
