Importing from PHP-Nuke to WordPress

I want to use wordpress instead of PHP-Nuke. At the moment I’m working with exporting database, I’m not an expert in this field and would like some help. After looking around the net it seems like using the rss importer that comes with WordPress is the best way. Is there anyone that knows how I could download the whole rss file from PHP-Nuke, I can’t find anything about this.