If you want to give your device a new identity by changing your device name just follow the steps
- Open the Terminal (Ctrl+alt+t).
- Write gksudo gedit /etc/hostname and press enter.
- Put the Administrative password and click on OK button.
- You can see current device name in hostname file. Rename it with your new device name.
- Save(Ctrl+s) the hostname file.
- If any other Document like Untitled Document 1 will open and want to save at the time of closing you can choose Close without Saving.
Try it yourself.