In one example, a jack adaptor is mounted to a trailer structure. A jack flange, which can comprise a jack flange extension, of a jack is inserted downwardly through an opening in an upper portion of the jack adaptor. The jack can be rotated to a position that misaligns the jack flange with the opening through which it has been inserted. The jack can then be actuated to raise the jack flange into engagement with the upper portion of the adaptor for use in raising the trailer structure. The process is reversed to disengage the jack flange from the adaptor to permit removal of the jack.