If you want to install the latest version of AcyMailing or upgrade to any commercial version, the upgrade process is as easy as the installation one!
You don't have to uninstall AcyMailing. Simply process as explained above and install the new package via the Joomla Extensions manager and AcyMailing will be upgraded without losing any of your data.
Log in the Joomla Administrator section and click on the menu Extensions -> Manage -> Update
Then click on Find Update if they are some check it and click in Update