I happened to have had a small piece of 0.100 inch thick stainless steel to slide between the alternator shaft and washer. This enabled the bolts to be screwed in about 4 turns each. Using a 10 mm socket and 1/4 inch drive ratchet, each bolt was turned by one turn in sequence. I could hear the fan hub bearing pop in stages as the bolts were turned. The bearing was seized on enough that the stainless steel plate bowed slightly.