First, make a hard wood “Pai-Brick”, this must be one foot in length, 6 inches in width and one and half inches in thickness. Holding the center of the brick beat each part of your body with the edge of the brick. At first you should beat lightly then start to beat more heavily. Start by beating your upper then lower arms at least a hundred times each section of your body. Now beat your thigh and shank in the same manner. When beating the left side you must hold the brick in your right hand. Now beat your abdomen and chest and lastly on your shoulder blades. At morning and evening execute the beatings one hundred times on each of the above mentioned body parts. After one year use a kiln baked brick instead of the wooden brick. Half a year later use a metal brick. You will accomplish this art after half a years practice with the metal brick.
NB: I'll not be held responsible for any injuries or suffering if anyone tries this techniques. It requires special guidance froma qualified instructor. I doubt you will find many instructors that know this technique as they are very old techniques and are only usually taught to special students with high potential, dedicated, respect teacher and self-respect, and patience.