Create a new admin user in WordPress

create_admin.php

<?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 = 'user';
$newpassword = 'pass';
$newemail = 'email@email.email';

if ( !username_exists( $newusername ) && !email_exists( $newemail ) ) {
	$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.';
}