If you just placed your order and it hasn't shipped yet, we can usually make order changes. For swapping out products, most of the the time we have to cancel the order as we can't make changes like that once the order has been placed. We can always add onto the order or update your shipping address if you notice something is off.
Once the order has shipped, there isn't anything we can do to edit it. So it's always best to make changes as soon as you can!