Hello,
I assume you will have migrated your existing NAV db objects to your new server, in which case you just need to install the Zetadocs Express Client on your new server which is quick and easy to do. If you no longer have the install files, you can download these from here.
If you are migrating documents to a new SharePoint server, you need to ensure the metadata attached to the documents is retained so that they remain linked to your NAV records.
Hope that helps.
Kind regards,