Remove buttons carefully, with as little damage to fabric as possible, and stitch up button holes. Stitch giant press studs (or hooks) to reverse side of button edge, positioning the corresponding half of the press stud (or eye of the hook) on top of the stitched up button hole.
That didn't make any sense at all. Why would you want to "change the direction" of a button and exactly what do you mean by "change the direction"?
