How to move/rotate an object's axis?

I want to move and rotate an object’s axis without moving the object and I can’t remember how to do this. Can anyone help?

You can either

  1. In edit mode, select all vertices and rotate them (bad).

  2. Use the “Axis Orientation Copy” script. You must have or create a second object or Empty oriented with its axes the way you want. In Object mode, select the object you want to modify, then Shift-select the object whose axis orientation you want to copy. Do Object menu->Scripts->Axis Orientation Copy and answer the prompt. It’s just like magic!

Um, why is the first option bad? I’ve done this a few times when I’ve realized that I’ve buildt everything backwards along Y than I wanted. Mind you I did a constrained 180 around Y …