Does anyone have a step by step approach for the refactoring code challenge?

// Task 1 of 1

// So at your new Java job, you've written a brand new Shopping Cart system for the website. After some developers have used the objects you created for a while, they ask you to make it easier to add things to the cart.

// Check out more instructions in Example.java. Once you implement their request, check your work, and you will pass the challenge.

public class Example {

  public static void main(String[] args) {
    ShoppingCart cart = new ShoppingCart();
    Product pez = new Product("Cherry PEZ refill (12 pieces)");
    cart.addItem(pez, 5);
    /* Since a quantity of 1 is such a common argument when adding a product to the cart,
     * your fellow developers have asked you to make the following code work, as well as keeping
     * the ability to add a product and a quantity.
     */
    Product dispenser = new Product("Yoda PEZ dispenser");
    /* Uncomment the line following this comment,
       after adding a new method using method signatures,
       to solve their request in ShoppingCart.java
    */

    // Step 1: uncomment line:
    cart.addItem(dispenser);
  }

}

public class ShoppingCart {

  public void addItem(Product item, int quantity) {
    System.out.printf("Adding %d of %s to the cart.%n", quantity, item.getName());
    /* Other code omitted for clarity. Please imagine
       lots and lots of code here. Don't repeat it. 
    */
  }
  // Step 2: Add new method
  // New Method does *not* have quantity as a parameter
  public void addItem(Product item) {
    // call the other 'addItem' method specifiying quantity of one:
    // adds with default quantity of 1
    addItem(item, 1);
  }
}

// No changes needed to Project.java