[Zope] Upgrading 2.0 to 2.3

[Albert Kinderman]

I have a site running on 2.0.1.  I would like to upgrade to 2.3.x.  I 
have searched for a how-to on upgrading, but I can't find it.  I have 
not been reading the list closely lately, but I did see a comment about 
exporting products from the old installation and then importing them to 
the new installation.  Is there anything that has to be done with 
Data.fs?  Should I export the top level folders and objects and import 
them into the new installation as well?

A pointer to a step by step guide would be greatly appreciated.

Al