I'm not sure I understand the question. The float hinges on a thin pin. When the bowl is full, the float holds the needle in its bore. When you drain the gas and remove the carb bowls, the float is free to hinge downward on the pin, allowing the needle to come out. The metal hinge pin can also slide out the side and let the float drop out of place.
It's no big deal - everything just fits back where it was, I was just letting you know so you don't LOSE any pieces....
(Photo courtesy of Pat's carb site)
