changeip question

hi... i need to change the subnet of my xserve... i presume i need to do so using the changeip command but i found this post [url]https://www.afp548.com/forum/viewtopic.php?forum=18&showtopic=12944&highlight=changeip[/url]... is that still accurate? if so, how does it work? if its not the case, and i need to use changeip, are there any specific ways to do so? ie: do i need to unplug the server from the network first? do i need to remove its entry from the DNS server first? if i'm not changing the host name, do i need to put it in the changeip command? once i've run the changeip command, and changed the ip in network settings, do i need to reboot the server? how can i check that the change of ip was 100% successful? ah i nearly forgot, how does it apply when your xserver has 2 network cards? thank you