Replacing a Backup DC/DNS/DHCP server

I have to replace an old backup W2k3 R2 Domain Controller. The other W2k3 R2 DC has all the FSMO roles.But it does not provide DHCP service.

What steps would be involved in setting up the new DC?. I am assuming no ADPrep/ForestPrep would be required since the current network is a single w2k3 domain.

Would it be OK if the new server had SP2 on it.
Any input would be appreciated.
Thank You.