About license combine question

I have rhino 6 for zoo license in network, now I prepare to buy another rhino 7 license. How can I combine new license into rhino 6 zoo license to multiplte computer use?
Thanks a lot.

Upgrades are the same license. Add it to the Zoo and you are good to go. You can still only use either 6 or 7 at one given time if you have purchased an upgrade.