They call them dowels? I seen locking cones around Hyster wheel studs before but I wouldn't call them dowels.

I've run into tough ones before but they all broke free via hammer. Maybe try an air hammer and penetrating oil?

Worst case, you could pull the axle and remove the wheel bearings, which you have to do anyway. Then pull the brake drum and wheel assembly as one piece. Only problem would be in trying to reinstall without damaging the grease seals. A wheel dolly would help.