Douglas, seeing that the steering wheel is not reusable, I would make a cut into the hub being careful not to cut into the threads on the steering column shaft. Then pry on the slot that you cut to try to open up the hub. From your profile it appears that you may have either a 70 or a 72 and are not sure. Which of these look most like yours?
Above is a model 70.
Above is a model 71.
Above is a model 72.
Above is a model 70.
Above is a model 71.
Above is a model 72.