Best way to upgrade is to plan ahead with proper backups of the environment. You can ask the SAS TS team for any known issues during this upgrade path and if there are any risks then you can put a mitigation plan to avoid that risk.
Upgrades can be scary, but with proper planning I am sure it can be successful without much issues or changes.
The SAS Users Group for Administrators (SUGA) is open to all SAS administrators and architects who install, update, manage or maintain a SAS deployment.