How do I delete backups that I put on a server, not in the cloud?
You have plenty of information on cloud backup. But none on how to manage the non-cloud backups.
I don't see how to get to the manager to delete them.
Using a Window admin user account, open Windows Explorer and click on This PC in the left pane. You should see Norton Backup Drive in the right pane. Double click on that and then look for the backup set that is stored locally. Double click on that backup set and you should see the folders and files in that backup set. You should then be able to navigate to and delete any files and folders by selecting them and right clicking and click on Delete.
You could also delete the entire backup set if you are finished with it by right clicking on the Backup set after double clicking on your Norton Backup Drive.