Modifying Your Login with Usermod
In order to change a login name, you will need to also copy the contents of the related Home folder. This can be done relatively quickly with a single command via the terminal (Applications > Accessories).
The following command allows you to change a login while also instructing Linux to move the existing Home folder to the new one that is created when the login is changed:
usermod -l newname -m -d /home/newname oldname
There are two ways of applying this change. If you are the administrator and are changing logins for other users, you shouldn’t have any problem applying this change from the main Ubuntu user interface. However, if you are a single user and wish to make this change, then you will need to do this from the Recovery Console.
You can access the Recovery Console after your computer starts by tapping Shift, which forces the GRUB Loader screen to open. From here, select the version of your operating system that is labelled (recovery mode) and when this has loaded, use the command above to change your own user login.