Print invoice from Iframe

[macyhvt]

Hi,
I want to change the layout of iframe invoice at virtuemart->orders->print button(screenshot attached).
Can someone please help me find out where to find the files?
Thanks in advance.

[Jumbo!]

The invoice layout files are -

components/com_virtuemart/views/invoice/tmpl/invoice.php
components/com_virtuemart/views/invoice/tmpl/invoice_history.php
components/com_virtuemart/views/invoice/tmpl/invoice_items.php
components/com_virtuemart/views/invoice/tmpl/invoice_order.php

Copy the above files to -

templates/YOUR-TEMPLATE/html/com_virtuemart/invoice/invoice.php
templates/YOUR-TEMPLATE/html/com_virtuemart/invoice/invoice_history.php
templates/YOUR-TEMPLATE/html/com_virtuemart/invoice/invoice_items.php
templates/YOUR-TEMPLATE/html/com_virtuemart/invoice/invoice_order.php

and make necessary customisations.