Luis Peel

This plugin provides a simple and powerful interface for managing custom post type slugs. With it, you can:
<ul>
<li>View: See a complete list of all custom post types registered on your site.</li>
<li>Edit: Quickly and safely change the slug of any custom post type. For example, you can transform “vehicle” into “car” for shorter and more descriptive URLs.</li>
<li>Delete: Completely remove the slug of a custom post type, simplifying your URL structure.</li>
</ul>
Example:
If you have a custom post type called “vehicle” with a URL like <a href="https://www.yoursite.com/vehicle/mycar" rel="nofollow ugc">https://www.yoursite.com/vehicle/mycar</a>, this plugin will allow you to change the slug to “car” to get the URL <a href="https://www.yoursite.com/car/mycar" rel="nofollow ugc">https://www.yoursite.com/car/mycar</a> or even remove it completely to have <a href="https://www.yoursite.com/mycar" rel="nofollow ugc">https://www.yoursite.com/mycar</a>.
Benefits:
<ul>
<li>Greater control over your URLs.</li>
<li>Flexibility to adapt URLs to your specific needs.</li>
<li>Ease of use thanks to its intuitive interface.</li>
</ul>

Custom Post Type Slug Manager

Easily edit or remove slugs for any custom post type. Customize your content URLs without coding.

Grégory Viguier

With this plugin, administrators can change the default author base in the registered users profile url, and the author slug of each user. 
Changing an author slug is a good thing for security (if your login is “This Is Me”, your slug will be “this-is-me”, a bit easy to guess). 
The plugin adds 2 fields for this purpose, one in permalinks settings, the other in a user profile.
<ul>
<li>Default: example.com/author_base/author_nicename/</li>
<li>Customized: example.com/jedi/obiwan/</li>
</ul>
<h4>How to edit the slugs</h4>
<ul>
<li>Go to Settings > Permalinks to edit the author base: “author” => “jedi”</li>
<li>Go to Users > “Any user profile” to edit the user slug: “agent-smith” => “obiwan”</li>
</ul>
<h4>Translations</h4>
<ul>
<li>English</li>
<li>French</li>
<li>German by <a href="https://wordpress.org/support/profile/carny88" rel="ugc">Carny88</a></li>
<li>Spanish by <a href="https://wordpress.org/support/profile/oliverbar" rel="ugc">Oliver</a></li>
</ul>
<h4>Multisite</h4>
<ul>
<li>The plugin is ready for Multisite.</li>
</ul>

SF Author Url Control

Allows administrators or capable users to change the users profile url.

Custom Post Type Slug Manager vs SF Author Url Control