What do I need to know about switching license keys?

Hi, I built my boss a website and I used my GP Premium license key from my own site (because it can be used on multiple sites). Now he wants his own license. We don't want any of our customizations to go away. Here is what I assume is the right path: I get him to visit generatepress.com and buy a premium license. Then we go into our [his] website's dashboard and copy and paste HIS license in the area where my license currently resides (aka the "Receiving Updates" field). Forgive me if this question is answered somewhere else- I couldn't find it. Anyway, we love y'all's theme (it's lightning fast). Thank you kindly and keep up the good work. Kate