You can do this at any time prior to payment by clicking on the shopping cart/checkout link in the shopping cart icon at the top right of the page. Simply remove or add items or modify your order as needed. If you change your mind after checkout then contact us immediately at info@drcarl.com.au. If we have not despatched your order then there is no charge to modify or cancel your existing order. If we have already despatched your order then you will need to return the unwanted goods for a refund. See Terms of use for more details about our refund policy.