remove proudly powered by

I know this is asked a lot of times in here but I could not solve it with my own website. I am new with wordpress and try my first steps.

I also don`t want to remove the whole line, just modify it with other text. I was told to look in the footer but in my footer there is no concrete text.
just:

<?php
/**
* The template for displaying the footer.
*
* Contains the closing of the id=main div and all content
* after. Calls sidebar-footer.php for bottom widgets.
*/
?>
</div><!– #main –>

<footer role=”contentinfo”>

<?php
/* A sidebar in the footer? Yep. You can can customize
* your footer with four columns of widgets.
*/
get_sidebar( ‘footer’ );
?>

<div id=”colophon”>

<div id=”site-info”>
<?php af_display_footer_text(); ?>
</div><!– #site-info –>

</div><!– #colophon –>
</footer><!– #footer –>

</div><!– #wrapper –>

<?php
/* Always have wp_footer() just before the closing </body>
* tag of your theme, or you will break many plugins, which
* generally use this hook to reference JavaScript files.
*/

wp_footer();
?>
</body>
</html>

I hope someone can help me with this.