Dave Stokes wrote a terriffic guide for upgrading from CS 2.0 to 2.1. After reading this guide I can't possibly imagine trying to do this on your own. Definitely get the guide. You have to register on his site, but the energy expended to tap a few key strokes is really worth the great information Dave provides.
Get Dave Stokes's Guide to Upgrade CS 2.0 to CS 2.1
About Dave
David Berman is an Entrepreneur and Business Systems Analyst Consultant. Through leadership, business process reengineering and strategic planning David transforms companies, enabling them to become more profitable, respond faster to changes in any industry, and become more competitive. David also manages inhouse or internationally outsourced software development projects when custom solutions are needed.