Hi

From the admin dashboard, go to Appearance > Montezuma Options > Main Templates > single.php.

Look for the section that looks like this:

<div id="main" class="row">

	<div id="content" class="col8">

		<nav class="singlenav cf">
			<div class="older"><?php previous_post_link(); ?></div>
			<div class="newer"><?php next_post_link(); ?></div>
		</nav>

		<div id="post-<?php the_ID(); ?>" <?php post_class( 'cf' ); ?>>

Remove the nav element so it now looks like this:

<div id="main" class="row">

	<div id="content" class="col8">

		<div id="post-<?php the_ID(); ?>" <?php post_class( 'cf' ); ?>>