Alright, so my petcock looks a lot like this one: http://www.treatland.tv/peugeot-motobecane-black-petcock-straight-flow-p/french-cock-black-straight.htm
I figured out how to remove the plastic cover over the switch, but it just covers a metal switch below it. What I need to know is how to get the round plastic cover BELOW the switch PAST the switch--the toggle doesn't seem to be removable but I am sure there has to be a way. Suggestions? Once I am in there I am very confident I can fix my current gas leak, just frustrated trying to take the thing apart.