I have the a wrong license number in one SQL Server. What's gone down is this: We virtualized a physical server, effectively cloning its software and licenses - SQL Server included. We want to repurpose the physical machine by keeping SQL Server and modifying its license to another license key that we have purchased. Would prefer not to reinstall SQL Server. Can it be done?
As long as you're only running the same number of instances as you have licenses, you're legal. We repurpose/move servers (and licenses) all the time. There is no activation in sqlserver and MS support has never looked at the current key when doing any remote troubleshooting.
The only way I've ever seen is to do it during installation. If the servers are the same edition / same distribution you should ok as long as you can prove your licenses.