Here’s how to change your WordPress username in PhpMyAdmin.
If you have access to the WordPress admin area, I recommend you use a search and replace plugin to change your username and email address.
However, if you are in the middle of a site migration or working on a staging site and unable to access the WordPress admin area, use the following MySQL command to replace the username.
1. Open your database in PhpMyAdmin.2. Click on the database name of your site to unfold the tables associated with it.
3. Click on wp_users. This is the table where the user information is stored.
4. Select the user you want to change the username for.
Look for the row user_login. The value in this field is the username of this user.
You can also change other values.
user_nicename → user nickname.
user_email → user email address.
display_name → user display name.
Press ‘Go’ to make the changes.
Do not type in and try to change your password here. If you want to change your password, first update your username and/or email address, then use the WordPress’s “lost your password?” function to update your login password.