Where can I edit the Postage / Shipping Label for Magento?
Is it in the back end? Or through the FTP?
Just need to edit the layout of the invoice that gets sent to the customer.
Use the translation file translate.csv in your theme. For demonstration purposes, I will use the default theme in the default package (app/design/frontend/default/default). You may apply the steps below to your custom theme.
How to change the label using the translation file:
Add a new line:
"Billing Information","Shipping and Billing Information"
Verify that your Store View uses the correct locale ("en_US").
Log in to the Magento backend and navigate to System > Configuration > General > General > Tab "Locale Options". The "Locale" has to be set to "English (United States)" (either by directly setting it for the particular Store View or by inheriting from the Website / Default configuration).
Verify that your Store View uses the default/default directory. This can be set in System > Configuration > General > Design. By default, "default/default" is used.
Refresh or deactivate the cache.
Navigate to the checkout page. The label text now should be "Shipping and Billing Information".
How to change the text only for Mage_Checkout texts:
If you want to change "Billing Information" only in these places where the checkout translation helper is used, you can modify the line in translate.csv like this:
"Mage_Checkout::Billing Information","Shipping and Billing Information"
Are you looking for edit layout of the Invoice or Postage / Shipping Label ?
Invoice and Postage / Shipping Label both are different.
posting this in answer as i am not able to comment