soak it down real good with some rust penetrant (WD-40) or equivelent. If its not stripped realy bad then you might still be able to get it out with the socket or a 7/8 wrench. Remember dont just try to break it loose by turning it loose, work it back and forth (even if its still tight) this will help work it free. If its too stripped out then try using some big vice grip pliers. hope this helps you out some.