As the trick description suggest, this trick happens switch, or backwards.
Take Off / Slide
When you jump onto the rail no great spin is necessary, as you only need a 90-degree rotation. As you jump, you should turn your head to look over your shoulder, naturally your shoulders and hips should follow as you rotate your head. The be all and end all is always body tension build, so make sure you keep relaxed. To get a secure landing on the rail, aim to land with equal pressure on both legs and watch that you do not over rotate as in this trick you want to rail slide right to the end. When leaving the rail resist the urge to spin so that you're forward facing, but instead come off switch. To get the rotation, but some pressure on the toes of your front foot.
After leaving the rail in the switch position, wait until your skis make contact with the ground and absorb the impact with bent knees and ride out. Rail landing are not always in great condition, so you should take a good look at them beforehand to avoid landing in a bomb hole.