https://www.newschoolers.com/ns3/web/content/videos.php?vid=26264&
this is just some screwing around on a rail, but it shows pretty well what to do if you look at it closely. just try to rotate mostly your lower body untill you get to 180, then snap your upper body around to keep your legs stalled out untill the end, and look at the end immediately which sets you up well to spin off.