2. To change IP you need to edit /etc/sysconfig/network-scripts/ifcfg-eth0 on your server in your favorite editor.
The current entry will look something like
You will need to change lines "IPADDR", "GATEWAY" and "NETMASK". All this information you received from our letter.
4. Also you need to edit/check /etc/hosts file and change your old IP to new (if it is needed).
5. Then restart networking using next command:
$ ifdown eth0 && ifup eth0
If that gives you trouble reboot the machine.
If the problem persists, please, let us know and we will solve it as soon as possible.