change username on ubuntu.

Below tutorial will show you how to change username in ubuntu 12.04 precise.First,we need login as root the change the username,then restart the enable this changing ,here we go.

1.Open a terminal by Pressing Ctl+Alt+t or search terminal in Dash

2.Unlock account root and enable login as root using below command

sudo passwd root
sudo sh -c 'echo "greeter-show-manual-login=true" >> /etc/lightdm/lightdm.conf'

sudo vi: /etc/lightdm/lightdm.conf:

　　autologin-user=root

3.Reboot your computer and login as  root

4.Open a terminal and Use blow command to change your username

usermod  -l newname oldname

5.(Optional)Now you already changed your username,but your home folder name still are “/home/oldname”,if you also want to change /home/oldname to /home/newname just run below command

usermod -m -d /home/newname newname

Note:Of course you can combine step 4 and step 5 using below command

usermod -m -d /home/newname -l newname oldname

6.All done,use below command to lock your root again,then you can reboot and login as your new username

passwd -l root