I know guys recommend applying heat but I'd only do that as a last resort. Heating and cooling parts can eff-up the relatively tight tolerances and the socket could shrink and clamp down even harder on the hex.
So the only way I was able to get mine out was to cut it a couple inches away from the cross member and whack it directly again and again with a sledge hammer.
Obviously if you're hoping to save the torsion bar...you may want to look into other options. They're never quite the same after you cut them.