To loosen the tapered dowels you need to strike the center of the axle cap with a heavy lead hammer (a big no bounce might work). You might then be able to spread the dowel with a thin screwdriver and wiggle them out.
I always carry a pair of "jamb nuts" in my tool box (not enough thread sticking out for regular nuts to be jambed together) for the stubborn ones...put the nuts on the stud and lock them together, then unscrew the entire stud like a bolt.
Mike B
