Just install on the new machine and use your serial number to activate it. You don't need to (can't) deactivate the current installation so don't worry about dealing with it.
So can I do the same thing to transfer it back? Also, I'm reading that
maybe I can use on 2 computers at the same time - know anything about that?
You aren't transferring anything. I doubt you read that you can use it on two machines at the same time. The license agreement normally entails the following... You are allowed to have two activated installations (that's two machines), only one of which can be using the software at a time.
So if you want you can have it ready to use on two machines and then use it on one at a time.
thanks for confirming what I have discovered today. This forum has been
far more helpful and informative than Adobe's call center. No
documentation with the product indicated this capability. I am relieved.