Impact gun might get them off.
If not remove the entire wheel, hub, and drum assembly. Weld a bar or something on the heads of the offending studs to prevent turning, then remove nut.
If you have a nut splitter or are real good and careful with the torch that's an option. In the end you'll still be removing the hub to replace the studs.
Last edited by Grigg; 02/14/2016 4:46 PM.