Just want to ask what is the effective old scars remover to use?

You didn't mentioned what type of scars you have. There are many different types of scars. However, scars fade with time. If your scars are over two years old, then you might want to have surgery to remove the scars. Scars that are mature or deep are very difficult to treat with over-the-counter products, and may need to be treated or surgically removed by a dermatologist or plastic surgeon.