Genesis and child theme licensing questions

[mjsdiaz]

I have read the FAQ and the forum answers and still don't understand the proper method for leaving credit to the original child theme developer if I heavily modify a child theme.

If I modify a child theme (css, functions.php, and home.php), I can rename the child theme and the theme folder it so it won't be rewritten in the event of an upgrade.

But how/where do I leave the credit for the original theme developer per the GPL? In the functions.php the 2 line below /** Child theme (do not remove) */? In the styles.css?

I know to change the Theme name at the top of css to my theme name, but then what is the proper way to credit the original child theme developer?

In the functions.php, what is the correct way to leave credit?

And also in the credits that are visible at the bottom of the website?

What is the recommended method for all of this to be ethical?

Thank you!