Yes, you can change the shipping address as long as the order has not been paid with Paypal or has been dispatched, simply login to your account online, go to My Orders and select the enquiry button next to the order and submit a job request with the details of the address you wish to have to goods delivered to.
Please note: Changing the address in your account page will not modify the address on your order.
Paypal
You will not be able to change the address on your order if you paid using Paypal. Your order will need to be cancelled and resubmitted with the correct address selected from your Paypal account