Pydio has an internal updater. I was however unlucky to find out that the upgrade from 6.2.2 to the latest version failed between 7.0.1. and 7.0.2. But I was lucky to have a backup so I did not have to repair but could just restore the whole machine.
So I decided, there must be a _more manual way to update just some steps. So here are my findings if anyone else got the same trouble.
If one enters the Settings and below the basic setting the plugin setting then the menu item action is found. Upon edit one can specify the update server.