Article in English: There are two types of shampoos that will help take color off of  your hair. Clarifying shampoo is rich in color-stripping ingredients and dandruff shampoo also helps strip color from your hair. These shampoos will help break down the color on your hair and get your hair back to its original color. You can also buy conditioner that is not safe for color treated hair. This will help keep your hair from getting damaged but also help pull more color from your hair. Make sure you get shampoo that is not safe for color treated hair, such as Suave Daily Clarifying Shampoo. The point it to strip the color, so you don't want it to protect the color on your hair. Sit in your bathroom with a towel around your neck. Wet your hair with water as warm as you can stand to open up your hair cuticles. Massage in the shampoo to your hair, lathering it from your scalp to the ends. Make sure you get shampoo onto all of your hair so the color will come out evenly. As you lather and spread the shampoo, remove the excess foam.  The foam should take on the color of the black hair dye. Make sure you don't get it in your eyes. Make sure you scrub your hair well in this step. You want to get your hair as saturated with the shampoo as possible. Now that your hair is saturated with the shampoo, cover it with a shower cap or plastic bag. Take a hair dryer and heat your hair evenly. Make sure you don't melt the material of the cap as you heat your hair. Once you've covered your whole head, let the shampoo sit on your hair for 15-20 minutes.  If you have access to a heated dryer, then you can sit under that instead. If your hair is long enough, you may need to clip up sections so it all fits into the shower cap. Once the 20 minutes are up, rinse your hair thoroughly. Taking a little bit more shampoo, lather you hair and rinse it twice more. This is to remove any of the excess color molecules from your hair that were loosened during the shampooing and heating process. There is no need to heat and wait between these lathers. Cover your hair...

Summary in Chinese:
购买正确的产品。 给头发抹上洗发水。 加热头发。 冲洗并重复以上步骤。 抹护发素并加热头发。 重复。