Summarize the following:
While you don't necessarily want to wash your hair before this vinegar treatment, you do need to be somewhere that can have a bit of vinegar dripping on it. You may also want to remove your clothes, so that they don't get covered in vinegar. While you can use undiluted apple cider vinegar, it can be hard on a sensitive scalp and can dry out your hair. Instead opt for a slightly diluted mixture, which will give you all the benefits of the vinegar but will be a little less harsh. Either spray it directly on your scalp or use cotton balls to apply. Remember to keep your eyes closed, so the vinegar doesn't get in them! You don't want the vinegar to just get on your hair and not your scalp. Take the time to make sure it thoroughly coats your scalp. Wrap a warm towel around your head to lessen the smell and keep the vinegar in place. The warmth of the towel will also open your pores, letting the vinegar really get into the pores. Because of the strength of the vinegar, you will probably need to shampoo and condition to get the smell out. Be sure to use products that are easy, or even helpful, to your scalp, such as shampoo and conditioner that contains tea tree oil. Because the concentrated vinegar can be hard on your hair and your scalp, you don't want to do it every day. However, doing this treatment regularly will help to keep the bacteria that causes dandruff away.

Summary:
Go into your bath or shower. Mix 1/4 cup apple cider vinegar with a few tablespoons of water in a small spray bottle or bowl. Apply the vinegar mixture directly onto your scalp. Massage the vinegar through the hair and deep into the scalp. Let the vinegar sit for around 20 minutes. Rinse your hair thoroughly. Repeat this vinegar treatment a few times a week.