Rename Bank Transfer in Checkout

I don't accept bank transfers, but do receive PayPal Mass Payments daily. As it is, for newbies to Mass Pay I have to send an email explaining how to do it. The Bank Transfer in OC is great for giving this info and I want to use it.

I don't care if it says Bank Transfer in the Admin, but I do want to have it say PayPal Mass Pay at the payment options during checkout.

I've spent the better part of an hour and can't find where to make the change, I would have thought under Language, but I found nothing there. (Too many years with CubeCart, I suppose.)

Give me a clue, where can I simply change the text that shows at checkout?

You mentioned you tried the language files. I see there is a language file for bank transfer in payments. Did you tried to update upload\catalog\language\english\payment\bank_transfer.php

No, I did not. Can't understand how I missed it. Even stayed sober and straight last night.

Thanks