How to Disable a WordPress Network
At some point, you may decide that running a network of sites on WordPress isn’t for you, and you may find that you want to disable the multisite feature completely. Before disabling the network, save any content from the other sites by making a full backup of your database and any files that exist in the /wp-content/blogs.dir/ folder.
The first step is to restore the original wp-config.php file and .htaccess files that you saved earlier. This causes your WordPress installation to stop displaying the Network Admin menu and the extra sites.
You may also want to delete the tables that were added, which permanently removes the extra sites from your installation. You can use phpMyAdmin to delete the multisite tables from your WordPress database when you want to deactivate the feature. The following extra database tables are no longer required when you aren’t running the WordPress multisite feature:
wp_blogs: This database table contains one record per site and is used for site lookup.
wp_blog_versions: This database table is used internally for upgrades.
wp_registration_log: This database table contains information on sites created when a user signs up, if they chose to create a site at the same time.
wp_signups: This database table contains information on users who signed up for the network.
wp_site: This database table contains one record per WordPress network.
wp_sitemeta: This database table contains network settings.
Additionally, you can delete any database tables that have blog IDs associated with them. These tables start with prefixes that look like wp_1_, wp_2_, wp_3_, and so on.
WordPress adds new tables each time you add a new site to your network. Those database tables are assigned a unique number, incrementally.