Once logged in, click on Subscriptions and click Edit to the right of the address. This only affects the shipping/delivery address, this does not update billing information related to the method of payment.
You will be taken to a page where you can modify any of the fields pictured below.
We also offer a guide on how to set up multiple subscriptions with different shipping addresses.
Customers can update their Shipping Address directly in their Customer Portal. You can link your customer to the Customer Portal using this guide.