Address changes on orders are rarely, but sometimes, possible.
We have a very small window after an order is placed to either make the change, or to cancel the order, so that it can be placed again.
Chat with us (scroll to the bottom of this page and use the link you'll find there to do so) during business hours, as soon as possible after the order is placed.
While this won't guarantee success, it will definitely provide the best chance of us being able to make the change or cancel the order.