A guy I know had the dreaded pinion bolt break off in the ring gear carrier. He tried the extractor kit and managed to break the extractor off too. I told him he is pretty much skewered. I suggested smashing the pinion shaft out with a BFH and a drift. He is timid about that. Then someone else suggested a Dremel tool and a carbide bit to get the hardened extractor out. He said to ask a dentist for old bits they didn't need. Does that make sense?