upgrading license

I have upgraded to Lifetime Pro licences for 2 seats. Running one on desktop just fine. I want to use the other seat for my laptop that presently running a free license.
Question I have is how do I upgrade or change my free license to use my Lifetime Pro license?
Many thanks

Hello Hank,
you need to deactivate the previous FREE license and then activate using your PRO license key.
All this is done in Menu>Help>License section of the desired device.

Also, since you are a PRO user, I suggest using out PRO support system - https://support.emclient.com