How do I Use my own crontab instead of WP Cron?

Some folks need to disable wp-cron for operational reasons – so the below is how to call the script directly via unix cron (or windows)
There is no “simple” way to change how cron works because the plugin uses WordPress events to communicate with the cron engine. However, you could simulate the “Update All Feeds” button which would have a similar effect. In a cron job (or manually), you could call:
http://(sitename)/(pluginfoler)/core/ajax/wp/update_all_feeds.php
and the plugin would reply with either “success” or fail +message.

A possible reference/guide: http://www.inmotionhosting.com/support/website/wordpress/disabling-the-wp-cronphp-in-wordpress