When you install on the third computer, you will be given the option to deactivate the other two computers. Do that, and then reactivate on the other of the older two that you still want to use it on.
Thanks ssprengel for this assistance, I will do this - one question - to reactivate, do I uninstall and reinstall the Creative Cloud Access thing ... how would you suggest.
Do appreciate your help!
You can de-activate by going into the software Help Menu. No need to uninstall unless you want to.