This is how I removed the ignition switch on a 1983 LeMans III but probably applies to all the bikes with a similar gauge panel.
The lock-ring is plastic and recessed into the gauge panel and tapered to align the panel to the framework below. The combination makes it impossible remove the lock-ring with pliers. Also the ignition switch is keyed into the metal framework so attempting to rotate the switch from below causes the innards of the switch to twist, but not the lock-ring.
My solution was to drill two 1/16" holes into the lock-ring, one on each side of the switch and then use snap-ring pliers to remove it. I used a pin vise (looks like the handle to a precision screw driver) to drill the holes. The lock-ring on the LeMans III is plastic so it worked well. The holes are hidden under the original folding key.
The lock-ring is plastic and recessed into the gauge panel and tapered to align the panel to the framework below. The combination makes it impossible remove the lock-ring with pliers. Also the ignition switch is keyed into the metal framework so attempting to rotate the switch from below causes the innards of the switch to twist, but not the lock-ring.
My solution was to drill two 1/16" holes into the lock-ring, one on each side of the switch and then use snap-ring pliers to remove it. I used a pin vise (looks like the handle to a precision screw driver) to drill the holes. The lock-ring on the LeMans III is plastic so it worked well. The holes are hidden under the original folding key.