You only need to perform the normal uninstall (based on your operating system) of Lightroom 5.
But I can't find any uninstall app or link.
I worry if I not deactivate and release the license. I may not be able to use on another computer for the old LR5.
This is why I want to make sure before I just delete the app of LR5 on my iMac.
There is no such thing as deactivation for Lightroom 5. All you have to do is uninstall it.
Thanks for the clarification.