Filter Hook for “twentysixteen_post_thumbnail()”

I set up a Plugin for a custom post type. In the single view, I want to include the thumbnail differently from the content-single.php template, showing it between “the_title()” and “the_content()”. The plugin filter hooks only work with WordPress objects, as far as I understand. How can I avoid showing “twentysixteen_post_thumbnail();” and “twentysixteen_excerpt();” without modifying the theme files or setting up a child theme?