Change rotation point for imported obj files


I just imported a 3d object made of a couple of obj files. a box inside another box. now i would like to use states to create two different versions where the center box turns around its own axis. since they are imported with the same base point so that their relation to each others match, the basepoint of the centerpice is now in the wrong spot for the rotatation parameter… is there a way to place an object and then change the center of rotation or scale?