[Dx4win] Vanity Callsign Change... How To?

[N6CKS]

I recently completed a vanity call change and have been in the process of
changing all the software associated with my old call.  How do I change
DX4Win to my new call?  Does it take a new license?  I am also wondering,
should I continue to add QSOs to my old callsign database or start a new
one?  Some advice from one of you that has already been through this would
help a lot!
Rory "Roy" Bowers, K6CKS