как установить старую версию dle на новую?

<?php
/*
=====================================================
 Billing
-----------------------------------------------------
 evgeny.tc@gmail.com
-----------------------------------------------------
 This code is copyrighted
=====================================================
*/

@error_reporting ( E_ALL ^ E_WARNING ^ E_NOTICE );
@ini_set ( 'display_errors', true );
@ini_set ( 'html_errors', false );
@ini_set ( 'error_reporting', E_ALL ^ E_WARNING ^ E_NOTICE );

define('DATALIFEENGINE', true);
define( 'ROOT_DIR', substr( dirname(  __FILE__ ), 0, -12 ) );
define( 'ENGINE_DIR', ROOT_DIR . '/engine' );

require_once (ENGINE_DIR . '/classes/plugins.class.php');

date_default_timezone_set ($config['date_adjust']);

include_once (DLEPlugins::Check(ENGINE_DIR . '/modules/functions.php'));
include_once (DLEPlugins::Check(ENGINE_DIR . '/classes/templates.class.php'));

if ($_REQUEST['skin']) {
	$_REQUEST['skin'] = $_REQUEST['dle_skin'] = trim(totranslit($_REQUEST['skin'], false, false));
}

if ($_REQUEST['dle_skin']) {
	$_REQUEST['dle_skin'] = trim(totranslit($_REQUEST['dle_skin'], false, false));
	if ($_REQUEST['dle_skin'] AND @is_dir( ROOT_DIR . '/templates/' . $_REQUEST['dle_skin'])) {
		$config['skin'] = $_REQUEST['dle_skin'];
	} else {
		$_REQUEST['dle_skin'] = $_REQUEST['skin'] = $config['skin'];
	}
} elseif ($_COOKIE['dle_skin']) {
	$_COOKIE['dle_skin'] = trim(totranslit( (string)$_COOKIE['dle_skin'], false, false ));
	
	if ($_COOKIE['dle_skin'] AND is_dir( ROOT_DIR . '/templates/' . $_COOKIE['dle_skin'])) {
		$config['skin'] = $_COOKIE['dle_skin'];
	}
}

if ($config["lang_" . $config['skin']] AND file_exists(DLEPlugins::Check(ROOT_DIR . '/language/' . $config["lang_" . $config['skin']] . '/website.lng'))) {
	include_once (DLEPlugins::Check(ROOT_DIR . '/language/' . $config["lang_" . $config['skin']] . '/website.lng'));
} else {
	include_once (DLEPlugins::Check(ROOT_DIR . '/language/' . $config['langs'] . '/website.lng'));
}

if( !$config['http_home_url'] ) {
	$config['http_home_url'] = explode("engine/ajax/BillingAjax.php", $_SERVER['PHP_SELF']);
	$config['http_home_url'] = reset( $config['http_home_url'] );
}

if (strpos($config['http_home_url'], "//") === 0) {
	$config['http_home_url'] = isSSL() ? $config['http_home_url'] = "https:".$config['http_home_url'] : $config['http_home_url'] = "http:".$config['http_home_url'];
} elseif (strpos($config['http_home_url'], "/") === 0) {
	$config['http_home_url'] = isSSL() ? $config['http_home_url'] = "https://".$_SERVER['HTTP_HOST'].$config['http_home_url'] : "http://".$_SERVER['HTTP_HOST'].$config['http_home_url'];
} elseif (isSSL() AND stripos( $config['http_home_url'], 'http://' ) !== false) {
	$config['http_home_url'] = str_replace( "http://", "https://", $config['http_home_url'] );
}

if (substr($config['http_home_url'], -1, 1) != '/') $config['http_home_url'] .= '/';


dle_session();

if (!$user_group) {
	$user_group = [];
	
	$db->query("SELECT * FROM " . USERPREFIX . "_usergroups ORDER BY id ASC");
	
	while ($row = $db->get_row()) {
		$user_group[$row['id']] = [];

		foreach ($row as $key => $value) {
			$user_group[$row['id']][$key] = stripslashes($value);
		}
	}
	
	set_vars('usergroup', $user_group);
	$db->free();
}

$config['charset'] = ($lang['charset'] != '') ? $lang['charset'] : $config['charset'];

$is_logged = false;
	
require_once (DLEPlugins::Check(ENGINE_DIR . '/modules/sitelogin.php'));
if (!$is_logged) {
	$member_id['user_group'] = 5;
}

if ($is_logged AND $member_id['banned'] == "yes") {
	die("User banned");
}

$Plugin = $db->safesql( trim( $_GET['plugin'] ) );

if (!$Plugin) {
	exit("Plugin file is not selected!");
}

@header("Content-type: text/html; charset=" . $config['charset']);

if (file_exists(ENGINE_DIR . "/modules/billing/plugins/" . preg_replace("/[^a-zA-Z0-9\s]/", "", trim(mb_strtolower($Plugin))) . "/ajax.php")) {
	include_once ENGINE_DIR . "/modules/billing/plugins/" . preg_replace("/[^a-zA-Z0-9\s]/", "", trim(mb_strtolower($Plugin))) . "/ajax.php";
} else {
	exit("Plugin file is not found!");
}
?>