Guidelines for upgrading freeradius installation? (3.0.19 -> 3.2.8)

Hi, all! Years ago (2020) I implemented a pretty basic freeradius installation (authentication only) in a school for WLAN access. That time I installed version 3.0.19 on a virtual server (Ubuntu 19.04) and used Samba to connect to Active Directory on Windows Server. This is still working fine but I think it is time for a larger upgrade of all involved components. Is there any recommendation/cookbook/guideline how to do that upgrade in the most efficient way with minimal effort? Of course I can do everything from scratch on a second virtual machine. Is that the preferred way? Or can I copy the freeradius configuration over? Any changes I have to do then? Your help is very welcome! Regards Uwe