First, read the English article below.

You will find that hair and soap residue may have accumulated underneath the strainer or stopper, which is located in or over the drain. Remove any screws securing the strainer, and remove the stopper by twisting and lifting it. Scrub any gunk or hair that has accumulated. Fill the kettle to the top with water, since there’s no exact measurement of how much water you should use. Allow the water to come to a boil. You can use a large pot to boil water if you do not have a tea kettle. This may instantly unclog the drain. Remember to avoid splashing the hot water, as it could burn you. Now, turn on the bathtub to see if it is now draining normally. If pouring hot water into the drain did not unclog it, use baking soda and vinegar to remove excessive gunk. Allow the baking soda and vinegar to sit for 15-20 minutes. You can use a timer to keep track of the time. Once again, fill the kettle up with water and bring it to a boil. The water will react with the baking soda and vinegar to unclog the drain. Test the bathtub to see if this method unclogged your drain, and try another method if this one did not work. Using baking soda and vinegar does not use any chemicals and generally works for small clogs, so this may not work every time. 

Now, please write a short abstract for it in Vietnamese. Abstract:
Làm sạch lưới chắn rác hoặc nút chặn. Đổ nước vào ấm và đun sôi. Rót thẳng nước sôi xuống miệng ống thoát nước. Rót 1/4 cốc muối nở và 1 cốc giấm trắng vào ống thoát nước. Chờ 15-20 phút. Đun thêm nước sôi. Rót thẳng nước nóng xuống ống thoát nước.