Remove Kriesi Link from footer without delete the footer

Hello !

I don’t know php and I have to remove the kriesi link in the footer, maybe replace it with another link.
I tried to modify footer.php but every change I make delete all the footer.

I don’t know how use the php functions you suggest in the file comment, I think I shouldn’t be able to use php to delete your link.
You should add a function in the theme option.

Thank you, happy day