01- Using your hosts MySQL administration tool (called usually phpmyadmin thru the MySQL menu), locate and select your WordPress database for your blog
This should open up your phpmyadmin window
Now select your database name
02– From your WordPress database, locate and select the WP_USERS TABLE (Note: the wp prefix may differ) and then click the BROWSE icon
03– Locate ADMIN and click the EDIT icon (on left) Continue reading WordPress: How to change the default ‘admin’ user login name?