Prerequisite(s): Make sure that both MDM servers are not running.
If you use pictures in your data model, do the following to migrate them to the new MDM server:
In the Jboss folder of the old MDM version, browse to:
Copy the upload folder of the old MDM version and paste it under the directory<$INSTALLDIR>\resources of the target MDM server.
Launch the MDM server and then Talend Studio of the new MDM version as usual and you should have access to the migrated data objects.