[Samba] migrate/change realm

[Rafał Sanocki]

Hi,

I have samba 4.5.15 running as ADDC, i need to change realm. How to do 
this in best way?
Using classicupgrade and create new domain using old privet files?  I 
don't want to lose database.
I can rejoin all computers in domain it's not the problem. But i need to 
save database groups, users.

Any ideas?

Rafal