Vuforia Studio 8.3.0 requires uninstalling any previous version first. Your projects and configuration will be preserved when installing Vuforia Studio 8.3.0
There is a listing in Support/Download for 8.3.0 but i think the installers are bad. The DMG (local install) is 0 bytes and the online installer errors out.
It's marked in the Help: https://support.ptc.com/help/vuforia/studio/en/
But I've read it elsewhere too, though can't remember where exactly