[ Plugin: postMash ] where do I put the code?

I am trying to reorder my blog posts, but the way I have my site set up, it’s not working. I call on category pages to work as multiple blogs, but I don’t know how to edit the code of a category page. postMash instructs you to use this code: <?php $readposts = get_posts(‘orderby=menu_order’); ?>

<?php foreach($readposts as $post) : setup_postdata($post); ?>
• <?php the_title(); ?>

<?php endforeach; ?>

but where do I put that?