Need help going from SBS 2011 to SBS 2012 Standard

I've searched the net for a while now and there is not good instructions on this. I know SBS is an oddball of an OS. Can I add the 2012 R2 server as a another DC and demote the old thus transferring roles? I know I have to update DNS, transfer DHCP, etc.

Any help is appreciated.

Thank you,