Swing out, make a half turn and swing back to the board. As you swing back out to the front end, let your legs swing behind you so that instead of rising to a stand position at the front end, you are horizontal with your legs behind you and your stomach down. Up to this point, the trick is identical to a face-off dismount. Let go of the bar with a half twist and quickly regrab the bar from underneath so that you are now back facing the 'right way' on the bar again.
You can find out more about this trick in my books:
Thanks to Kyla and Jean Francois for providing videos for this page.