How to nulled this script

<?php
    }

    function run_wpc_theme($old_value, $new_value){
        $old_license_key = $old_value['wpc_license_key'];
        $new_license_key = $new_value['wpc_license_key'];

        if($old_license_key != $new_license_key){
            wpc_run_api($new_license_key);
        }
        else{
            $r = array(
                    'status' => 'fail',
                    'message' => 'Invalid license key.',
                );
            die(json_encode($r));
        }
    }

}


function wpc_run_api($license_key = false){
    if(!$license_key){
        return false;
    }

    $postdata = http_build_query(
        array(
            'license_key' => $license_key,
            'domain' => site_url(),
        )
    );

    $opts = array('http' =>
        array(
            'method'  => 'POST',
            'header'  => 'Content-type: application/x-www-form-urlencoded',
            'content' => $postdata
        )
    );

    $context  = stream_context_create($opts);
    $r = file_get_contents('http://www.yuppythemes.com/wp-content/plugins/wp-licensing-for-theme-and-plugin/ltp-api-activate.php', false, $context);

    $r = json_decode($r, true);

    if($r['status'] == 'ok'){
        wpc_activate_wpc_options();
        add_action( 'admin_notices', 'wpc_api_admin_notice__success' );
    }
    else{
        add_action( 'admin_notices', 'wpc_api_admin_notice__error' );
    }
    die(json_encode($r));
}

function wpc_api_admin_notice__error() {
    $class = 'notice notice-error';
    $message = 'WPCanvo: Invalid license key.';

    echo '<div class="'.$class.'"><p>'.$message.'</p></div>';
}

function wpc_api_admin_notice__success() {
    $class = 'notice notice-success';
    $message = 'WPCanvo: Success!! You theme was activated successfully.';

    echo '<div class="'.$class.'"><p>'.$message.'</p></div>';
}