1. First make a backup of the following files.



cp /etc/hosts /etc/hosts.back cp /etc/hostname /etc/hostname.back



2. Edit the ‘hosts’ file:



vi /etc/hosts



The file should look like this:



127.0.0.1 localhost 127.0.1.1 your_new_hostname



Here, change “some_hostname” to the new hostname / computer name.

3. Edit the hostname file:



vi  /etc/hostname



This file only contains your hostname so change it again to the new_hostname

4. Now restart the hostname and networking services:



service networking restart



it could be that you will disconnected for a wail. after this re-login and check your new hostname with:



hostname -f



- See more at: http://www.unixmen.com/change-hostname-ubuntu-13-10/#sthash.EYB6bzAf.dpuf