To submit a new version of an existing entry (e.g., a new edition of a book) to the publication server, go to "Manage deposits" and look for the existing item in the table. If the item is already published, please note that you have to select the Live Archive checkbox to view the published items.
Now open the item you have a new version of by clicking on the icon "View Item". You get to the details page of the item where you can perform different actions by choosing the "Actions" tab.
Here you find the button "New Version". It will create a copy of the item and you are working with this new version from then on.
As soon as this version gets published, it will be linked to the older version of the item. Please note that the system may generate links to non existing entries if the older version is not publised to the live archive.