In order to update your SPSS license you are required to obtain an authorization code through ITS. 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. When you start the wizard you should see an image similar to the following:
Make sure License my Product now is selected as in the image. Click next until you get to the following window (or something similar):
Copy and paste the authorization code received from ITS in the proper box and then click next. Follow the rest of the prompts to complete the authorization process. Full instructions are on your installation CD.