Adress

It is technically possible to change the address at any time in the order process. 

Please see Orders - Changing an order for more information about changing addresses (e.g. consequences shipment)

To change the address (same procedure in Magento applies for Billing Address and Shipping Address)

In the address details select Edit

A pop up will appear which will allow you to change the address

Make the changes and select Change Order address to save the changes