Need help with image tag

I need help replacing an image tag.

The original code:

<a href="<?php echo get_settings('home'); ? rel="nofollow">">
<img src="<?php bloginfo('template_url'); ?>/images/logo.png" alt=""/>
</a>

The image is hosted in the media library at this URL: https://mytestingsite.us/wp-content/uploads/2012/12/roc.jpg

How do I switch out the “/images/logo.png” that’s in the original code to the new image?