Step 1: First, put the sweater and clothes into the washing machine. Before washing the washing machine, put an appropriate amount of cold water in the washing machine, so that the washing machine will be washed with cold water when it works periodically. If your sweater has buttons or other decorations, put it in your underwear bag before washing it. Step 2: When the sweater is put into the washing machine, add a cup of white vinegar. Step 3: Then take the sweater out of the washing machine, put it in a bucket or a filling bucket, cover the sweater with enough water, then add a liquid clothes softener and let the sweater clothes soak overnight. Step 4: Wait until the next morning, then put the sweater and clothes into the washing machine again, and let the washing machine rotate the excess water on the sweater and clothes during the dehydration cycle. If it is a sweater with buttons or ornaments, it is still necessary to put the clothes in the underwear bag to prevent the sweater from dehydration and deformation. Step 5: When drying the sweater, please use a low-calorie dryer to dry it. In this way, after washing and drying, the sweater will properly restore its previous softness. It takes only five steps to soften a sweater. Once you learn it, you don't have to worry about wasting your beloved sweater when it becomes uncomfortable to wear. The softened sweater will still be warm, and it will not be afraid of cold in winter.