I don't know a thing about it, but I'll give you some
advice. Go up the street, past the boarded-up shopwindows near the barrel-fires of dawn's last
drunkards, and strip down to your sneakers.
Once you've done that, you should be ready for the inscription. You'll need something sharp; a bit of glass does nicely, but in a pinch, a large splinter of hard wood will do.
Carve a voluntary wound on your inner thigh, in the shape of a rectangle, about two inches by three. You'll need to get detailed now: you have to carve the entire lineage of your clan, mother's side only, inside the rectangle. Their ancient secret symbols should all fit, five generations back. If you don't know their symbols, you can spell their names out, but you'll have to write small, perhaps even abbreviate a bit.
Once the inscription is complete, you should then recite it, silently. Make sure to move your lips, but don't make any sound. And don't staunch the blood, just let it drip. Once you've recited the entire lineage, twice forward and once backward, then you'll be ready for the run.
Run at least six blocks. Try not to deviate from a straight line; if you have to, climb over obstacles. If you come to an obstacle you can't surmount, go around, but you'll have to run a few extra yards at the end.
Spin around in a circle three times as soon as you've stopped running. Then you can staunch the wound in your thigh with an old rag.
There should be a coffee shop nearby at this point. If there isn't, find one. Go in and order a cup of coffee to go. Black coffee only. Don't worry if they throw you out for being naked and bleeding, that's a good sign.
Take the coffee and mix it with some dirt and pebbles. Blow on it once, then throw it into the river. (If there's no river near where you live, a lake will do...but running water is more effective, so try to find a river or at least a stream.)
By this time, it should be around sunset. Find a cast-off blanket to cover yourself with; curl up in the darkest nook you can find, but make sure you're only enclosed on three sides. You must sleep at least six hours.
In the morning, tie the blanket around yourself like a toga. Climb to the highest point you can reach (a bridge or a tall building is ideal) and bow to the western sky.
Make sure not to take a bath for at least a week after this: urban rituals require grit.
Then, if all goes well, you will receive notice in the mail of the results.
Yep, take my advice. That's how you should do it.