Hi Jeewani,
The documentation from your example says (a bit higher up the page)
If you create the checkout process, you can either use the predefined Checkout wizard and Checkout step page types from any of the e-commerce sample sites, or create your own Checkout wizard and Checkout step page types from scratch (see Creating wizards on websites).
So what you can do basically, install a sample Dancing Goat or eCommerce Sample website, export Checkout wizard and Checkout step page types and import into your solution. Or write your own from scratch.