The Guest Author Name plugin allows you to publish posts by authors who are not in users of your website. You can also replace the URL. Note: If you do not add a URL, the author will not link to an existing user.
How to install this plugin
Method 1: Install this plugin using the built-in plugin installer: Go to Plugins > Add New. Under Search, type “Guest Author Name” Click Install Now. A popup window will ask you to confirm your wish to install the Plugin. Click Proceed to continue with the installation. The resulting installation screen will list the installation as successful or note any problems during the install. If successful, click Activate Plugin to activate it, or Return to Plugin Installer for further actions.
Method 2: Download the plugin.
In the WordPress admin panel, click on Plugins. Select Add New to get to the “Install Plugins” page. Click on browse and choose the downloaded file.
Click on the “Install Now” button to install the plugin. Once the plugin is installed, select “Activate Plugin”. Method 3: (Advanced Users): Unzip the file. Using FTP, upload the guest-author-name folder to the contents/plugins folder in your WordPress directory.
When you create a new post, a box will display under your post content. If you do not see this box, click on “Screen Options in the upper right hand corner and click on “Guest Author”
Save and view the post.
Your screen should look something like this (there may be other meta boxes in the area below the post).