You've been given a lot of good advice. Here is what I did just yesterday with a broken spring bolt on a '68 W300. The bolt broke off flush with the surface of the spring perch on the front axle housing. I took a 4 1/2" grinder with a very thin cutting wheel held vertically over the top of the bolt. I lowered it into the bolt and cut a slot that would allow a substantial screw driver to fit. Then I heated the bolt with my torch until it was bright red, held a piece of paraffin wax on the surface, sprayed it with PB Blaster, and then let the whole thing cool down. After a while I took a small chisel and tapped on the slot in a counter clockwise direction until it moved slightly. Then I put the screw driver in and screwed the bolt out. It was extremely easy. JH