Hi! You would pass the class name into the_widget(), so it would indeed be something like:
the_widget( 'TribeVenueWidget' );
You can also pass arguments across as in Snorton’s example in the thread you linked to – full documentation for the_widget() is available here: http://codex.wordpress.org/Function_Reference/the_widget
I hope that helps – but as this is really custom development territory we cannot assist any further with this one and will go ahead and close the thread. Of course if you have any other questions please don’t hesitate to let us know (by creating new threads).
Thanks!