Changing DNS on Cisco Call Manager

Our Current Version of Call Manager is "Active Version: 5.1.1.3000-5 "  I have inherited the IT position at the facility and can get into the box but because of a server failure we are working through we need to change the DNS on our call manager server to a  new address.  What are the commands and where do I change them.  I can get into the box at a console level and also through web administration to the OS administration.  The Ethernet settings only have options for me change the IP and subnet mask.  Any help is greatly appreciated we have Pilot Points that are not working and we are hoping this will resolve the issue, plus it needs to be done anyways since the DNS servers are no longer functioning.  Also there are two callmanager servers will these settings filter over or will I have to change them on both servers.