How can I flip a magnet so the north and south poles are now opposed?

I'm working on an animation on how opposite charges attract and same charges repel.  I've been asked to have a pair a magnets, have one flip over, and then move away.  The moving part is easy.  Any thoughts on how to animate one of the magnets so that it flips?  I've tried spinning and other effects, without much luck.

Thanks!