1. Turn the trousers over and carefully open the seams on both sides of the trousers with scissors until they reach the thigh circumference.

2. Measure the length, thigh circumference and leg size of trousers with a ruler, draw points with chalk, then connect the points, cut off the excess part of the line with scissors, and pay attention to leaving a seam of about three centimeters.

3. Sew the trouser legs with the sewing machine, lock the raw edges of the trousers with the sewing machine, and iron the trousers.