Thanks for writing in! It's possible to customize, but you need to setup a child theme first and activate it by following our guide here (https://theme.co/apex/forum/t/setup-how-to-setup-child-themes/57).
Then copy the file
_landmark-header.php in the following location
/wp-content/themes/x/framework/legacy/cranium/headers/views/integrity/_landmark-header.php into your child theme's respective location
Then you should be able to locate the text under the following condition.
<?php elseif ( is_search() ) : ?>
<header class="x-header-landmark x-container max width">
<h1 class="h-landmark"><span><?php _e( 'Search Results', '__x__' ); ?></span></h1>
<p class="p-landmark-sub"><span><?php _e( "Below you'll see everything we could locate for your search of ", '__x__' ); echo '<strong>“'; the_search_query(); echo '”</strong>'; ?></span></p>
We also have a customizations best practices guide available here (https://theme.co/apex/forum/t/customizations-best-practices/205).
Please note that we do not provide support for customizations. If you have further customization requests on this, I would suggest you to contact a developer or a service.
Thanks for understanding.