I have a question involving FBX objects and their pivot points and rotations in world space.

Can you rotate the pivot points without rotating the object? What I mean by that is can you change the face of a cube that the z, x, or y axes point to? (E.g. There is a dice and the z-axis points through the 3 face and I want to the z-axis to point through the 5 face, but I want the dice to look exactly the way it does in the level right now). All of the walls (FBX objects) have a rotation of (0.0, 0.0, 0.0, 1.0) meaning that they are all parallel. I want walls that are at 90 degree angles to each other, but none of the walls are according to unity, and I can't figure out how to change the rotation of the pivot points without the entire wall moving with it. Thanks in advance.