In order to update your SPSS license you are required to obtain an authorization code through ITS. Please go to http://www2.nau.edu/stat-lic/spss to register. Once you have your authorization code you will run the License Authorization Wizard. This may be found on your start menu if you are running windows or under application and SPSS on the Mac. Note: The version of SPSS is tied to the authorization code, so a code for version 30 will not work with version 31, etc.
The following may be slightly different on your system based on the version of SPSS that you are using. For example, this is showing SPSS 31.
Renewing your License:
Windows & Macintosh
Full documentation for SPSS may be found on the SPSS site at IBM SPSS Knowledge Center