I have a 1983 Yamaha Virago 550 (XV500K), and I want to replace the two spark plug wires.  I ordered the replacements expecting pre-cut wires with connectors on each end.

I received wires with separate connectors for the plug ends, but no connectors for the coil end.  The plug end connectors have a screw which screws into the cable's conductor, but I cannot see how to disconnect the old cables from the coils.

At the coil end, there is a "boot" which screws off exposing a hole where the spark plug wire enters, but I cannot seem to remove the wire.  If I try to screw it out, it does not seem to rotate.  I'm afraid to screw or pull the wire from the coil to hard since it might break off.

Does anyone know how to remove the spark plug wire from the coil?  

HI; try a little WD40 on the ignion wire. Let it set for about 1/2hr. then twist it back and forth. It should twist out. It has been in that hole a long time and the rubber may have bonded to the side of the coil. If you have to you can remove the coil and work on it at a table for easy access..hope this helps scruffy