Migrate Public Folders from 2003 to 2010

Hello,

I am at the tail end of our Exchange Upgrade.  The only thing left is public folders.  I have setup replication and all public folders have been replicated from 2003 to 2010.    The next step is to  Move all replicas.  My question if replication is current, how long with this process take?  Our Public Folders DB is around 30GB.

Also Do I need to remove the 2003 from the replica servers before moving?

Thanks