Pranav Pathak

<p>The Username plugin helps to change username of admin, without effecting other user’s username. First it will check if same username is exist or not. if same username is not exist, then only it will update existing user’s username. Every administrator can change only his/her username from admin panel.</p>
<p>After activation there is a sub menu in Settings called Username. Click on this and there is an option to change Username. Insert your new username and then in settings there is an option <strong>Click to check username is exist or not</strong> Click and check user is exist or not. If username already exist then it will alert you as <strong>Username In Use!</strong> in red color, else it will alert you <strong>Username Not In Use!</strong> in green color. If username is not exist and user click on submit then it will update username and it will redirect to login page. Now login with new username.</p>
<p>Note Password remains same. It is completely safe.<br />
If you are not redirect to login page that means Username is not changed.</p>
<h4>Requirements</h4>
<ul>
<li>WordPress 3.5.1 or greater</li>
<li>PHP 5.2.6 or greater (5.3 recommended)</li>
<li>MySQL 4.1.2 or greater (5.x recommended)</li>
</ul>


Username

The Username plugin helps to change username, only if username is not exist and without effecting others user's username.

Trân Minh-Quân

<p>This plugin lets you change user’s login username. It changes user_nicename as well so that your author link will correspond to your new username.</p>
<h3>Languages</h3>
<ul>
<li>English</li>
<li>Français</li>
<li>Swedish</li>
<li>Vietnamese</li>
</ul>
<h3>Credits</h3>
<p>Translators:</p>
<ul>
<li>Erik Billerby: Swedish</li>
<li>Igor Oliveira Ferreira: Brazillian Portuguese</li>
</ul>


WPVN – Username Changer

50% of the entire code circles around "level_can_use", i.e., role/level-based authorization, which has been deprecated many moons ago.
Additionally, it only allows to rename your own username.



Outdated & Limited

This plugin lets you change user's login username. It changes user_nicename as well so that your author link will correspond to your new username …

Username vs WPVN – Username Changer