Not sure how familiar you are building Kayfun style RTAs, but it sounds to me like a wicking issue. The most likely way for
juice to get down there would be for it to come up the juice channels, flood the coils and come down the hollow screw on the build deck.
Anyway, to get those sections apart, just keep unscrewing it and you might hit a lot of resistance as the O-ring gets to the edge, depending on the O-Ring it can be really tight. On one of mine, it opens and closes just fine, on the other it felt jammed and required a lot of force to unscrew. Replacing the O-ring solved the issue. I also got it wet with PG to act as a lubricant for when I screwed it back on.