To Upgrade a Dimension license (ie: stand alone to concurrent license), you will need to un-install the old license, then install the new license.

• Un-install the old Add-on license:
• Click on File/Administration/Install add-on license (Ribbon bar) or Admin/Install add-on license (Classic Toolbar)
• Select the Add-on Product from the Add-on Product pull-down menu
• Click on the “Un-Install” button. 

• Un-install the old license:
• Click on File/Administration/Install Software License (Ribbon bar) or Admin/Install Software License (Classic Toolbar)
• Click on the “Un-Install” button. 

• Install the new license:  
• Click on File/Administration/Install Software License (Ribbon bar) or Admin/Install Software License (Classic Toolbar)
• Type in the new Installation password in the "Installation password" box
• Click on the "Auto-Gen" button

• Install the new add-on license:  
• Click on File/Administration/Install add-on license (Ribbon bar) or Admin/Install add-on license (Classic Toolbar)
• Select the Add-on Product from the Add-on Product pull-down menu
• Type in the new add-on Installation password in the "Installation password" box
• Click on the "Auto-Gen" button