Unfortunately, it is not possible to change the options after finalizing the purchase. If your order is still within the cancellation period, please access My Page > Orders/Shipping to cancel your initial purchase and proceed to re-order with your desired options.
If your shipment is already out for delivery, please fill in a request for a return via Support > 1:1 Inquiry. Please refer to the FAQ's "How do I apply for an exchange or return?" article.