Either use the tub stopper to close the drain or cover it with a steaming hot cloth. Keep the drain closed for 30 minutes. During this time, the foam will be working on wearing down the clog. Use a small, sink size plunger to agitate the clogged-up material. Create a seal and push up and down on the rubber base of the plunger. Plunging works best if you fill the tub or sink with water. The added pressure from the water will help force open the clog. If the drain is clogged with hair, take a metal hanger and twist it till you have a long piece of metal with a small hook at one end. Carefully feed the hook end of the wire down the drain. Twist the wire around and try to snag the clog. Gently pull the wire back out once you've caught the clog. Take care not to scratch your sink or tub with the exposed metal. Also, use caution when untwisting the hanger. The metal may be sharp. A drain snake looks like a long metal rope. You'll need to carefully feed the snake into the drain. When the snake gets stuck, you'll want to turn the cable. This will make it catch onto the clog. When you slowly pull the snake back out, the clog should clear. Flush with water and repeat. Wear work gloves since the metal snake can be sharp. You should also have an old towel and bucket handy to set the clogged material.

TL;DR in Vietnamese:
Đậy kín và để hỗn hợp nghỉ. Hút thông đường ống. Dùng móc để kéo rác ra khỏi điểm tắc. Dùng dụng cụ thông tắc đường ống dạng dây.