I don't mean to insult your intelligence but, if since you don't know how to set the IP address on the server, it is possible you don't know how to edit your autoexec.ncf file either. At the system console type "load install". At the install screen select "modifiy autoexec.ncf" BE carefull - DO NOT select CREATE an autoexec.ncf -- you will delete your current one if you do.
Once you are in the edit mode use your arrow keys to scroll up and down until you find the the load statements mentioned in the other response. When your modifications are done you ned to save your autoexec.ncf.
Once this is done you have two choices, either reboot and let autoexec.ncf do its thing or unload your NIC and reload it. To do this just type the load commands in the autoexec.ncf for loading your network at the console command line in the order they appear in the autoexec.ncf. Since you appear new to this I highly suggest you just reboot the server.
ralph