To upgrade Newsletter Studio to a newer version you just need to upload the latest release file into the developer-section of the Umbraco and run the installer, we'll take care of any changes between the versions.
There are some things that you will need to consider
Version 1.1 Improved SMTP-connection tester. New button to Newsletter Analytics to ”Copy to new”. Added sender email and subject to Newsletter Analytics. Removed some dependencies from the class that holds the sending thread. Added button to ”clear” filter when editing mailing lists. UI imporoved w…