I've flopped numerous AMD cards in and out of my computers chronically. I simply remove the old card, put in the new, then reinstall drivers. Have yet to have this fail....the driver install performs without problems, at least for me.
Latest was removing a 5670 and replacing it with a 7770....did what I wrote and after installing the driver package (did NOT driver clean, etc.), the card's running perfectly and no system anomalies.