This is a pretty easy trick but you have to get a feel of how fast the rail slides first. You have to know how to Ollie and F/S 180.
Ride toward your target at a pretty fast speed but be comfortable with it. Ollie up over you rail, do a 90 degree turn FS, and push you feet down when you're on top of it. Then be ready to slide.
Balancing is generally easy for boardslides. Keep your weight centered, keep your shoulders parallel with the board, and keep your body over the board. It may sound difficult, but it is very simple. It is written above to go fast because balancing on a rail while going fast is much easier than going at a slow pace.
Slide until you're close to the end. Then, when you're about half a foot away from the end, do another 90 degree turn either BS or FS then just slide out. Be sure to get the timing right, or you may smack your trucks against the rail prematurely, and that definitely isn't a good thing. And always remember to turn out while still on the rail, because trying to turn out after the slide is complete is near impossible.
It's a fun trick to do on rails but on ledges it's a bit too easy. Come at a 45 degree angle if you find coming parallel with it is too hard. Shove out is below.
To do this, it would help to know how to do a BS Boardslide to fakie. There must be an end to the pole and you must be able to get on both sides. 1. Get on to the rail and slide. 2. Make sure you are well balanced. 3. When you get to the end, shove the board 90 degrees and do a little body varial to land on your regular position (Goofy or Regular) 4.Ride away and look cool while you get mad props.
Click Here to View the Video – Jason