You should first upgrade to rc5, then to 2.0, then to 2.0.2 and then to 2.1 ;)
Anyway, is not that hard as it may sound. Until version 2.0.2 (2.0 to 2.0.2), as far I can remember, all migration needed was simple sql scripts. So, if you run them in order, you'll be fine. Then just follow the steps to migrate from 2.0.2 to 2.1.
Rafael
[originally posted on jforum.net by Rafael Steil]