Where is this page located?

I'm trying to change some text on the "Step 5:Payment Method" page. I've found some other posts but they don't seem to have info where those pages are located within Opencart.

When the page is in a browser the URL is "www.mydomain.com/cart/index.php?route=checkout/checkout

Is the file I'm looking for a php file or a tpl file and how does one change a tpl file?

Please select the preferred payment method to use on this order.

CREDIT CARDS
Visa, MasterCard, D

Thanks

Just sent you an email on how to change it.

DL

I would like to know the same? Can you post as to how to change it please?

The template file for that page is /catalog/view/theme/default/template/checkout/payment_method.tpl