Usually as long as the ball socket on the assembly is still good, you can remove the hex nut at the end of the shaft and the broken parts can then be replaced. Put some lock tight on the stud before re-installing the hex nut. You might have to clamp the collar of the shaft with a vise grips to get the hex nut off. Put some white grease on the ball to lubricate it. Or, if available, you can replace the whole assembly.
