its always the little things...
if it was steel in steel i usually place a steel nut over the snapped bolt/stud and fill the nut up with the welder ..then unscrew it if the weld is good and the heat has done its thing.. but steel in alloy..! could be tighter than a nuns......shoe laces...
good luck dude
but remember...easy outs snap to!! use a bigger one before you force it too much