[Plugin: Co-Authors Plus] Replace authors with coathors in List Category Posts widget

If you know how, can you please tell me how to replace authors with coauthors in a widget? The widget I’m using is “List Category Posts”. I just want both authors to appear, without links. I used some shortcode…

function mr_coauthor_shortcode() {
	echo '<p class="byline">by <span class="coauthors">';
	if(function_exists('coauthors_posts_links'))
	    coauthors_posts_links();
	else
	    the_author_posts_link();
	echo '</span>';
}

To place the coauthors in my byline but I can’t figure out how to simply replace all instances of “the_author” with “coauthors”. Should I just make a function like the above? If so, where do I call it?