Hi, luvmykids2
You're right, you need to remove the brass cable fitting after removing the set screw. The brass fitting does just pull out, but after 40 years it may be a bit reluctant to move. Try attaching the end of an old cable to give something to grip on in a vice and PULL!! Alternatively, you may be able to get a wedge or a soft drift inside between the speedo pinion and the other side of the fitting to start things moving.
Good luck,
Graham