If you have DHCP enabled, you can connect your ILO port to your network and access it via a browser using the the ILO name which is usually ILO$SERIALNUMBER. Ex. http://ILOUSE000000. The default username is Administrator and the password is printed on a sticker on the server itself.
Once you are connected, you can change the IP address to a static IP by going to Administration –> Network and disable DHCP and enter in your network information. You can also add or remove users as well.