Perhaps you had your Grow Social Pro license active on one of your sites and realized you want it on a different site instead. Here's how you'll accomplish moving things over.
Log into your Mediavine Marketplace account, click account in the upper right corner and click account details.
From there you’ll click Manage Sites
Then you can deactivate the current site and update the new domain.
After changing the domain, you can install Grow Social Pro on your new Dashboard by following the instructions in this help doc.