Hey,
It took me 2 hours, but i found it. Really embarrassed it took me that long, but what can you do.
Anyhoop – if you go to display.php, and indeed on line 28 you have the line of code. All you need to do is delete the code that says class=”wp-email-capture-submit”, and then the button will use whatever is in the value=”” as the text on the button.
I’m guessing that trick will work for everything else too.
Good luck, and I’m hoping the guy who wrote this plugin learns a thing or 2 about being user friendly, cause that was ridiculous!