The following is a summary of the Pro version installation process. The complete and detailed installation instructions, for both the Free and Pro version of WPSSO Core, are available here.
Updating to the WPSSO Core Pro version is simple and easy — click on the “Purchase the Pro Version” button on any WPSSO settings page. After your purchase, an email will be sent to you with an Authentication ID and installation instructions.
The WPSSO Core plugin and its extensions use the WPSSO Update Manager (WPSSO UM) free extension plugin to check for Pro version updates. If you haven’t already installed the WPSSO UM extension, please see the WPSSO UM download and installation instructions here.
Once the WPSSO UM extension has been installed and activated, enter the unique Authentication ID on the SSO > Pro Licenses settings page. After saving the changes, an update for WPSSO Core will appear on the WordPress Dashboard > Updates page. To install and activate the new Pro version, update the plugin from within WordPress (as you would any other plugin).
If you use a WordPress multisite configuration, enter the Authentication ID either on the Network SSO > Pro Licenses settings page (to license several sites at once), and/or in the individual site / blog SSO settings. Note that the default site / blog must be licensed to allow Pro version updates from the Network admin interface.