Log into your Vectorworks Customer Portal or use the link provided by your distributor.

Run the installer. Ensure you enter your serial number correctly; the serial number often determines which language modules are activated. 3. Adjusting System Settings (macOS)

It is important to note that changing the language isn't just about the text on the buttons. (like those for the Dutch or German markets) often include:

Since the language is determined by the installer, the most reliable way to switch languages is to reinstall the software using the correct installer.