I was able to easily fix mine -- don't see it as being significantly more difficult than replacing.
Root cause appears to be that, as delivered from the factory, all of the current going to the headlights passes through the switch's contacts, causing them to heat up and distort.
I STRONGLY suggest that anybody that runs into this problem install headlight relays. This will cause the headlight current to bypass the switch and SHOULD prevent this problem from happening again. Our host sells a nice relay kit from jwest -- instructions were spot-on for my '86 and the relays took around 10 minutes to install.
Here's a link to the relays
Pelican Parts - Product Information: JWST-911-HLPR