NFC tags are reusable. When an object is retired, you move its tag to another object without swapping the tag physically. A tag only ever belongs to one object, so it takes two steps: unlink first, then reassign.
Step 1: Remove the old link
Open the previous object → Edit → click the tag in the Linked tag field → Unlink tag → Save. The details are in Remove an NFC tag link.
Step 2: Reassign
Either from the tag page: scan the tag or open it under Tags → Link object → select the new object → Assign.
Or from the new object: object → Edit → Linked tag → select the now free tag → Save.
Afterwards the tag page shows the new object, and a scan opens that one from now on.
A note on the history
The history is fully preserved — nothing is ever deleted from it. Take-outs and returns booked with the tag on the old object remain traceable there.