I had the same problem. Anyhow, here the “simple” solution (put it in your preamble):
\let\tmp\oddsidemargin
\let\oddsidemargin\evensidemargin
\let\evensidemargin\tmp
\reversemarginpar
Cheers,
Chris
Edit: Contrary to the previous solutions, the provided code does not change the style of the document 🙂