The payment acceptance mark helps visually indicate to your customers the different form of payment methods that are accepted during checkout such as Amex, MasterCard or Amex. It can be changed in the same way as any static text through the site's Admin > Languages page. Click on edit for the site and language of your choice.
Drill down the tree node, where <_default> is the standard templates or your portal number if you have created custom display templates. <StandardX> is which ever template version you're currently using.
Look for the resource name and change the text (or HTML) to how you want it to be shown. Save and your cart summary will start using the new localized acceptance mark.