How to Upgrade your phpNuke Application?
Before you proceed with the upgrade procedure, please make sure that you have created a full backup of your web site.

Step 1: The first step is to download the latest stable release of phpNuke on your local hard drive. You can download it from the official php-Nuke web site. Then you should replace the current phpNuke script files with the newly downloaded ones. This can be completed through your cPanel -> File Manager or using an FTP client.

Step 2: Edit the config.php file and enter the database details of your outdated phpNuke installation through cPanel -> File Manager.

Step 3: Find the correct upgrade package in the upgrades folder of the newly downloaded files and upload it in the public_html/nuke folder. Then access the file through your browser. If you see the following message:

PHP-Nuke Update finished!

You should now delete this upgrade file from your server. This means that the upgrade was successful.

For example if you want to upgrade from phpNuke 7.9 to phpNuke 8.0, you should upload the upgrade79-80.php file from the upgrades/8.x folder.

Then you should open the following URL:
http://www.yourdomainname.com/nuke/upgrade79-80.php
where you should change yourdomainname.com with your actual domain name.

Congratulations! The script upgrade was successfully completed.