If it is a price difference in your favor, which is when you prefer a product of lesser amount, we will make a normal exchange, and once we receive the shoes that you do not want, we will proceed to make the refund in the same way that the original payment was made. If it is a price difference in our favor, which is when you prefer a higher price product, prior to confirming the change we will send you the information to make the payment of the difference by paypal or bank transfer.