You should be pretty good at skateboarding before you try this trick. You have to know how to b/s Boardslide first.
Come up to your rail and do a 90 do it at a pretty fast speed. At first when you try you will probably stop on top of the rail or slide a little bit. You will learn how much to lean after about 10 tries. Then just keep practicing and you will get it. Its not so hard if your B/S Boardslide is mastered. Then when you are trying to come out of it just do a 90 and you should be fine. You can learn cool stuff like shove-it outs and things like that but whatever.
Click Here to View the Video – Austin