Hi craigjbradley. If you want to customize your invoices, just follow our article on custom form templates. It will guide you through the process and even has a very informative video to make it a bit easier. But to just change the address, just follow these steps:
Go to Settings ⚙ and then select Custom Form Styles.
Select New Style.
Select the type of form you want to create.
Once you do this, you'll be presented with the template customization window where you can select the address field and make the change. If you need anything else, just stop by and reply.