This trick is frontside. So approach the curb the way you would for a basic 50-50.
Ok to tailslide, approach a curb/funbox/whatever going at a moderate speed like if you want to slide farther then go faster. Act as if you are going to do a 5-0 grind, but instead of just landing your back truck on there, turn your board 90 degrees sideways, and land your tail on there. BE SURE TO KEEP YOUR TAIL DOWN (on the curb) AND YOUR NOSE IN AN UPWARD SLANTING DIRECTION (of the curb). Slide Slide Slide. Then if you can get this part down, coming off of a tailslide is easy -- just lean forward. After you get the hang of it, it rules!
It is important, while you're sliding... that you don't lean back too much because you slip out a LOT on this trick... and you do NOT want to land on the corner of a ledge.