How to convert WordPress multisite main site into a single site installation?

Introduction

This is a tutorial on how to convert your WordPress multisite main site into a pure single-site installation. This tutorial assumes the following:

• You only want to moved your multisite main site into a single site installation. You don’t care about any of your subsites.
• You are using Apache web server (that uses .htaccess)
• You are using Prime Mover PRO plugin. If you are using the Prime Mover FREE version, you need to upgrade to a paid version. PRO version is required to move the multisite main site.
• You don’t want to delete any of your existing wp-content/uploads/ files, plugins and themes.
• You want to use the same domain name after being converted to WordPress single site.
• You want to use the same hosting server (you don’t want to move to another different hosting).

Complete steps

• Create a single-site package of your current multisite main site using Prime Mover PRO. Make sure it is of single-site format.
• Download a copy of that single-site format package to your Desktop just to be sure you have a local copy. The original copy will still be saved in the /wp-content/uploads/prime-mover-export-files/1/. Do not delete this, you will use this later on.
• Just to be sure, manually backup all of your files and database so you can restore it just in case you need it back.
• Now you have done backup and creating a single site format. It’s time to delete your entire current WordPress multisite database. 
• Create a new WordPress database using the same database name as it was before (so you don’t need to change wp-config dB credentials).  This new WordPress database should be empty. WordPress and Prime Mover will fill this up with content later on.
• Open your wp-config.php and delete all multisite related constants. Make sure you removed all multisite constants in wp-config.php. For example these are the multisite constants common to all multisites:

/* Multisite */

define( 'WP_ALLOW_MULTISITE', true );
define('MULTISITE', true);
define('SUBDOMAIN_INSTALL', true);
define('DOMAIN_CURRENT_SITE', 'yourexamplesite.test');
define('PATH_CURRENT_SITE', '/');
define('SITE_ID_CURRENT_SITE', 1);
define('BLOG_ID_CURRENT_SITE', 1);
define( 'COOKIE_DOMAIN', $_SERVER['HTTP_HOST'] );

• Open your .htaccess and removed all of the current syntax. Simply empty your .htaccess – make it blank.
• Open your site in the browser to install WordPress. Example: https://yourexamplesite.test/wp-admin/install.php
• Proceed to install WordPress until it’s done.
• Now you have a fresh single site WordPress installation working – login and activate Prime Mover PRO. Enter the license key.
• Go to Prime Mover -> Packages. You should see your single site package there.
• Now restore it, once restoration is done – re-save your permalinks so the .htaccess can be updated.
• Done – your site is now successfully converted as a single site installation.

Conclusion

In summary, it’s very easy to convert your existing WordPress multi-site main site into a single site installation using Prime Mover PRO.