First off, I am not too good at this trick. I can land them, but not all the time.

Step 1: First you HAVE to be able to do F/S 180's and F/S 5-0's real good. B/S Noseslides can help. Before trying this trick, ride straight toward a curb about the hieght of your box or the curb you are gonna learn these on. When you are about a foot or so away do a F/S 180 and land in a tail stall. You will need to practice that until you can do it nearly every time.

Step 2: Ride toward the box or curb at about a 45 degree angle for learning, you can go straighter after you learn them. Start a F/S 180 but don't turn all the way. Slap your tail on the legde when it is almost 90 degrees over it (if you wait until your tail is completely 90 you won't slide, you'll just keep spinning and just tap the curb). Put a pretty good amount of pressure on the tail so you will slide. You have to kick your feet forward like on a Noselside. It's kinda like puching it along. Keep your balance kinda like a 5-0. Slide until you can't slide anymore. To come off simply twist your body and legs in the direction you wan't to come out. I've noticed that comming out regular is easier, but you might be one of those fakie people.