1-Think about this trick as a cross between a frontside bluntslide and a frontside 5-0 grind, for a good visual rendition.
2-Approach the obstacle you want to grind as you would for a normal 5-0 grind, with possibly a little more speed. Have your feet set for a normal ollie.
3-ollie up towards the block as you would for a 5-0 (don't level out; instead land with all your weight on the back truck).
4-Lean slightly inside the block instead of leaning slightly out from the block. You want the nose of your board to be pointing at about 45 degrees in from the edge of the block. Think of it as a 5-0 grind that you start to turn backside 180, but stop.
5-Lean back to get this trick to grind further.
6-Keep your shoulders facing forwards (the way you are traveling) while your hips point in the same direction the nose of your board is pointing (so your body is twisted like a frontside bluntslide).
7-Do a frontside turn to come out of the trick. Give a little pop of the edge of the block as you would to dismount from a 50/50 grind.