Secondary DHCP Server

We are running our DHCP service from Mac OS X Server 10.5.6. Recently this has been dropping out due to an underlying problem on the server. What I want to know is how easy is to to set up a secondary DHCP server on another one of our Mac OS X 10.5.6 servers. Does anybody know the steps. I have exported the config from the first server, and imported it into the second, but am hesitant to enable the server, as I am sure there must be more steps to it. Cheers.