You username cannot be changed !!
hehe....apa pun bisa klo punya hak akses Root
sign in to cpanel
- Using your hosts MySQL administration tool (I.E. phpmyadmin), locate and select your WordPress database
- From your WordPress database, locate and select the wp_users table (Note: the wp prefix may differ) and then click the browse icon
- Locate admin and click the edit icon
- Under the user_login column, change admin to your preferred WordPress administrative login name and then click go
Thats it, you should now be able to login with your new administrative WordPress login username. 
