Look in your /etc/sysconfig/network-scripts directory to see if you have file(s) such as:
which would be the default (RH type) of NIC interface conf file.
If you have this, then you could just edit the values in that file to reflect the co-lo's settings they gave you.
I believe CentOS kept the same structure as standard RH, but I've yet to have time to play with that distro.
Make a backup of original files in a separate directory just in case, and once you get the server to the co-lo and it's hooked up, test it just to be sure it's working (you never know when a type may have happened unnoticed!)
You did not say, but if you have a control panel package installed, then there may be other changes needed as well.
I am sure that if they have you all of that info then it has been setup for you.
I think the co-lo did not provide the server to him, he has it in his possession and will be taking it to the co-lo later this week. What I get from his post is that the co-lo has given him the numbers to plug into his server before he brings the server to them. That's how I read it anyways