Things to consider before starting software upgrade:
Upgrade your floating license. See detailed instructions.
Upgrade your modeling tool. See detailed instructions.
Upgrade your plugins, for example, SysML plugin. Check compatibility tables to find compatible versions of the plugins you need to upgrade. See detailed plugin upgrade instructions. If you're using your own or third-party developed plugins, contact their developers/owners for new versions and update instructions.
Upgrade the collaboration tool you are using: