From an Uprise position, slide down to hanging at the backend. Essentially the opposite movement to an Uprise. As you reach the back end, push your self backwards slightly from the bar, and with your arms straight, drop back into a swing.
It is possible to drop down and change your grip at the same time (for example changing to a Mixed Grip) which then helps connect other tricks straight after.
You can find out more about this trick in my books:
Thanks to Gordo and Renato for providing videos for this page.