samba - Jul 2010 - Migrate AD to SAMBA 4

is there any way to migrate w2k3 AD to SAMBA 4 and make samba4 live as
AD . 

I am able to  join samba4 to w2k3 AD as DC but not able to promote
samba4 to main DC and deactivate the present w2k3 server.

Can some help 

TIA 

Regards
Abhi