A small diameter, clear piece of tubing is put over the bleed nipple and led into a container. You have one person IN the car---you have one person at the brake (FURTHEST from the master cylinder). The person at the wheel shouts "DOWN" and opens the bleed nipple---the person in the car pushes down on the brake pedal, HOLDS it down and says "down". The person at the wheel then closes the bleed nipple and when it is closed, says "up"--the person in the car takes their foot off the brake pedal and says"up" This simple proceedure is repeated until clean, new brake fluid comes out of the bleed nipple. This proceedure is repeated at all 4 corners, finishing at the wheel NEAREST the master-cylinder. As well as looking for new brake fluid, one must check that no air bubbles are coming down the clear tubing (the reason why you must use clear tubing). You only need to open the bleed nipple about 3/4 turn for this proceedure. Tedious, slow, but very effective.