This is possibly the hardest skateboarding grind there is, apart from the Kasper Slide. To do this trick you must be very advanced and proficient in all basic grinds, especially the boardslide.
Approach your grind object at a very high speed. ollie and start a slow kickflip while turning to get into a boardslide position. Catch the board with one foot on the underside of each kick once the board has made a half rotation. When you come down you should be grinding on the griptape. This is very hard because it is rough, so it makes it a very bumpy ride. You will quickly lose speed, so make sure what you are grinding isn't long. When you come to the end of the object kick down on the board to finish the kickflip, then ride away.