I bought a used lens version I of the Canon 28-70mm F/2.8 L and the screw brackets brackets were broken on the fixed barrel. I bought a replacement part (YG9-0323-000). This is the part with the AF/MF switch and the zoom window. However, the new part did not come with the AF/MF switch or cable attached. The old one should work, but I cant figure out how to remove it from the old part. Does anyone know how to remove the switch from the fixed barrel? Alternatively, does anyone know where I can buy a new AF/MF switch and cable?
My advice. Call Canon, send the lens in for repair. Get back a great lens and hopefully take some photos. Its important to place value on your time.
USCamera-dot-com sells replacement parts and pdf manuals. They may be able to provide what you need.
Since the lens is not listed on the Canon service page it is likely that you will need a third-party repair shop. Folks on this forum speak well of Midwest Camera for repairs.
"The old one should work, but I cant figure out how to remove it from the old part."
That is probably an indication telling you, you need professional service. Consider, how did this part get broken? If it was because of a fall or hit, the lens may also need calibration. Canon service will check out the entire lens not just replace the part.