Create WP User via PHP file.php

// ADD NEW ADMIN USER TO WORDPRESS
// ----------------------------------
// Put this file in your Wordpress root directory and run it from your browser.
// Delete it when you're done.

require_once 'wp-blog-header.php';
require_once 'wp-includes/registration.php';

// CONFIG
$newusername = 'your_username';
$newpassword = 'your_password';
$newemail = 'your_email';

// Make sure you set CONFIG variables
if ($newpassword != 'your_password' && $newemail != 'your_email' && $newusername != 'your_username') {
	// Check that user doesn't already exist
	if (!username_exists($newusername) && !email_exists($newemail)) {
		// Create user and set role to administrator
		$user_id = wp_create_user($newusername, $newpassword, $newemail);
		if (is_int($user_id)) {
			$wp_user_object = new WP_User($user_id);
			$wp_user_object->set_role('administrator');
			echo 'Successfully created new admin user. Now delete this file!';
		} else {
			echo 'Error with wp_insert_user. No users were created.';
		}
	} else {
		echo 'This user or email already exists. Nothing was done.';
	}
} else {
	echo "Whoops, looks like you didn't set a password, username, or email before running the script. Set these variables and try again.";
}

?>