Include the Php301Mapper class to your header file. Add the following to the top of your 404 loader page.
$redirects = [
'/index.php?page1OLD' => '/index.php?page1NEW',
'/index.php?page2OLD' => '/index.php?page2NEW',
'/index.php?page3OLD' => '/index.php?page2NEW',
];
MapFactory::Mapper($_SERVER['REQUEST_URI'],$redirects)->run();
composer install