The Woocommerce Events Manager plugin is fully developer-friendly. You can follow the steps below if you want to change or override any part of the Category organizer list page design.  If you have experience customizing WooCommerce templates, it will be effortless for you. It’s like Woocommerce templating. First, you need to create a new folder in your active theme folder and rename it as mage-events:
Now, please go to wp-content/plugins/mage-eventpress/templates folder and copy the file taxonomy-category.php or the taxonomy-organozer.php file and paste it to the theme-folder/mage-events/ folder that you just created in the theme folder. You can change any part of the code in the template files. Suppose you want to change the grid style to the list style of the event list on the category page. You need to change the code line 17:
do_action('mep_event_list_shortcode', get_the_id(), 'three_column', 'grid');
and change it to:
do_action('mep_event_list_shortcode', get_the_id(), 'one_column', 'list');
  Happy Developing!