linux change user name

http://askubuntu.com/questions/34074/how-do-i-change-my-username

mkdir ~/home/<newname> -p <password>

sudo adduser -U <newname>:<newnamegroup> 

cp ~/home/<usertocopy ~/home/<newname> sudo -- usermod -l <newname> -d /home/<newname> -m <oldname>
sudo --  groupmod -n <newgroup> <oldgroup>