How to Move My WordPress MU Install

1. Log in to your WordPress installation. Click 'Settings' and 'General.' Type the URL to which you are moving your WordPress base files in the 'WordPress address (URI)' field. Type the URL for the blog site in the 'Site address (URL)' field. You do not need to change the URL if you are only moving the WordPress installation to another server and it will remain in the same directory and at the same URL. Save your changes.
2. Open your FTP program. Connect to the server where your WordPress MU installation is hosted. Copy all files in the home directory to your new website, server or directory. Open the '.htaccess' and 'wp-config.php' files and change all instances of the URL if applicable. Save your changes to these files and upload the edited copies of the files to your server.

3. Log in to your Web server's administration panel. Open “PHPMyAdmin” and load the database associated with the WordPress multisite installation. Click 'Search' and then search for the server URL in your database. If you have changed the WordPress installation directory or URL, you need to edit every table referencing the original URL and update it to the new URL. Click 'Edit' next to each table entry to edit it. Click 'Go' to save your changes.