First, reach the ledge or rail at a moderate speed next go do a Kickflip, but do a 90 degrees turn and immediately after you catch the board you do a Tailslide it might take you to do this but once you master this you do a shove-it out and its not that hard, because all you have to do is push. This trick is all around hard and it'll take you a lot of practice but. Its all cool and don't be afraid because if you are it'll just make your chances of getting hurt.
Good Luck!
By: Tom-E