Actually, I just tested this in my lab. What I did was just rename the existing data-set to "-old" or something and SM-SQL does not see a data-set anymore. After that I ran the "configuration wizard" and SM-SQL created a new data-set.
I agree that you will not be able to restore from the old data-set using SM-SQL, this you need to do manually. But for this is enough.
Cheers,
Hans