well if your talking different licenses and sites you will make sure the proper license you want to upgrade has current members access and download the files for that license from that specific members area and then perform an upgrade. Upgrade documentation is in the documentation folder of the downloaded code.
Yes Chuck, it's for the same website. I respect license for all products. I'm using your products since 3 may be 4 years. For my new website, I've buy a few weeks all of your products to make this better than ever