Invoice for Purchased Product
To download invoice for your purchased product, navigate to your Purchase History. If your transaction is not Refunded, you will be able to see a 'Invoice' button (see below image).
Click on 'Invoice' button to download a PDF version of invoice.
To change address in Invoice, navigate to Edit Profile. There you will get 'Address' tab, click on that and change address fields. Same address will be reflected in the Invoice.