I wish to ADD a "buy now" button on product page , and redirect to checkout page after clicking it without adding the product into cart. I noticed that a similar question was been asked before Woocommerce - Add To Cart and Buy Now buttons on Product Pages
But this method only redirect to the checkout page but still adding the corresponding product into cart.
How can I achieve this? Many thanks.
------update 10/7/2015----------
I think the best way to do it is to create another cart and checkout instance, But I just don't know how to implement it , Could anyone help me ?