How deactivation free/demo eM Client before install a licensed version

I just bought a Pro license after a few days of using the DEMO version.
In the message I received from the eM Client with the license, I am informed that I must deactivate the demo version.
But I can’t find the TAB where the license is deactivated. (activation only)
I attach a print screen to see what appears on my monitor.
My questions:
a) I appreciate the help to deactivate the free version and install the licensed, clean version, deleting all files from the free version.
b) A final question: Please, do any of the forum members have a tutorial in Portuguese?
Thank you all and good health in this terrible phase of the pandemic that affects us all.!

eM_Client-Menu_Help_License-Screenshot_1

If there is no Deactivation option, that means that a prior Free or Pro License has not been activated on that computer.

Just click on Activate and paste in your key.