You don't. They are molded onto the shaft. If you are very careful you can sometimes open the crimp, where the wire is crimped to the end of the shaft, enough to get the old wire out. That is quite difficult to do and requires the patience of a saint. The best bet is to try to find a repop knob (those have a way to fasten them to the shaft if the original knob is broken) or locate a cable on ebay or at a swap meet.
The Swap Meet link was added automatically by the forum, not me.
Last edited by Tiny; 05/24/2008 12:27 AM.