If the method below is no longer working, please try using the add on here. It must be updated to the latest version in order to work:  All-In-One-Migration-Unlimited-Extension

If you need to import a rather large website export from the All-in-One WP Migration plugin, you may see an error message that your file size exceeds the file size limits. They offer an Unlimited Extension upgrade, but it’s not free.

Instead, you can make a single change to the plugin’s codebase to bypass their filesize limitation.

Change in all-in-one-wp-migration/constants.php (line 239 in current version) :

//define( 'AI1WM_MAX_FILE_SIZE', 536870912 );
define( 'AI1WM_MAX_FILE_SIZE', 536870912 * 100 );