Need to decommission a Windows 2003 server....

Question

I have a Windows 2003 DC with all the FSMO roles.  It was the first DC of the domain
I also have 3 other DCs that are Windows 2008 R2.  
All of the DCs are global catalogs.  
DHCP Server is running on the Windows 2003 DC.  
All of the DCs run DNS Server but a majority of the PCs in the network point to the Windows 2003 DC for DNS resolution.
1) What do I need to do to get rid of the Windows 2003 DC cleanly and efficiently?  Is there a certain order of steps? 
2) How should I split the FSMO roles between the remaining 3 Windows 2008 R2 DCs?
3) I want to split the DHCP between the 3 DCs.  Should I copy the DHCP database from the Windows 2003 DC and import it?  Or should I recreate 3 non-overlapping scopes?

Answer 1

To migrate the FSMO roles have a look at this guide
http://support.microsoft.com/kb/324801 which explains all the steps. Once everything's been moved you can demote the server so it's no longer a DC, though personally I'd opt for shutting it down where possible initially, just so it's still there
if you find something hasn't been moved. Once you're happy everything is still working without it being there then make sure you demote it, otherwise you'll end up with old records hanging around. If you want to make absolutely sure you could have a look at
http://msmvps.com/blogs/acefekay/archive/2010/10/05/complete-step-by-step-to-remove-an-orphaned-domain-controller.aspx which details the steps required if a server isn't cleanly removed and you end up with orphaned records.
Not sure about the splitting of the FSMO roles to be honest. I suspect realistically your best off keeping them all on the one server, since it will make management a lot easier (eg you know which one server is more important than the others), and of course
if you split it then rather than having a 1 in 3 chance if one of the servers died of having to recover that info, you'd now be guaranteed problems regardless of which server died.
For DHCP there's a guide here for how
http://blogs.technet.com/b/networking/archive/2008/06/27/steps-to-move-a-dhcp-database-from-a-windows-server-2003-or-2008-to-another-windows-server-2008-machine.aspx for how to move DHCP to another server. In terms of multiple servers, unless you want to
go for a full on DHCP failover setup, splitting the scope is the best option, since you can't have multiple DHCP servers actively giving out the same IPs. I haven't tried it to be honest, but since the scope it only a part of the DHCP settings, I'd suggest
you should be able to use the above process, import those settings to each DHCP server, and then once imported edit the DHCP scope on each such that they no longer overlap. That way you ensure that all the other settings remain the same and are completely
identical.