Delete and add two iPhones

Good morning and first time posting in the community.  I'm also a brand new Norton 360 (Windows) subscriber.  Let me apologize upfront if this is a stupid question. I currently use three licenses as follows: Home PC and two iPhones.  Next week my wife and I are (each) buying a new iPhone to REPLACE the two we currently have.  I'm looking for the easiest way to delete the two iPhone licenses we have and add the two new ones.  Of course, when we purchase the two new iphones we're going to transfer everything over from the old phones right in the Apple store.  I'm looking for a "how to" with the hope of causing the least disruption to my Norton 360 account.