I do the vinegar soak, but it rarely frees up the spool. Next step is needle nose pliers, with a rubber band or inner tube around the spool for grip/protection.
The spool really is cheap enough (my LDS usually just throws one at me for free, but it's like a buck or two) where you might as well replace it whenever this happens, but I've replaced the o-rings and reused the spool before too.
The spool really is cheap enough (my LDS usually just throws one at me for free, but it's like a buck or two) where you might as well replace it whenever this happens, but I've replaced the o-rings and reused the spool before too.