If you want to change the computer name of your Ubuntu box, here are 6 steps for you to get the job done
1. Open the Terminal.
2. Edit the hostname file:
gksudo gedit /etc/hostname
3. You will be asked the Administrator password. When prompted, enter the administrator password and OK to continue.
4. Replace the current computer name with the new name in the hostname file.
5. Click Save.
6. Close the window and reboot your Ubuntu.
After rebooting, your computer will have a new name!