Synchronization Project upgrade fails

After the upgrade from 8.0.2 to 8.1.4 I noticed that Synchronization Projects are still 8.0.2. This causes issues like that one during the schema update.

Error updating schema of system connection (One Identity Manager (ONEIDMT-DB-01\OneIM))!
The element (Domain) cannot be removed from list (Properties) of object (Active Directory site (ADSSite)) because is it still being used by other elements.

There is a way to start the upgrade manualy?

The guide suggests DPR_Migrate_Shell, but I don't know how to use it.

Thanks