How to activate a license on a different windows computer

Hi, I bought Secure Line (1 license) and I have installed the software on two windows 10 Computers. I read in this forum that you can install it on multiple computers but you can use the license just on one at a time. Now, how can I transfer/activate the license on one Computer and deactivate it on the other?
Thanks,
Thomas

Same way as you did on the first system.