Pour boiling water into a laundry tub, sink, or bucket. Immerse only the waistband into the water using a large wooden spoon. Keep it in the water for 10 to 15 minutes. Pull up from the legs or use the wooden spoon. If you're worried about burning your hands, wear rubber gloves. Wring the waistband in a towel. Throw them into the dryer. Use high heat and dry. The waist should shrink temporarily.

How would you rephrase that briefly using Chinese?
用水煮裤腰。 把裤子从水里捞出来。 弄干牛仔裤。