You can do this as follows. But this is a parent theme change. So, please note this change and reapply after theme upgrade.
1) Please do remember to back-up the file prior to any changes.
2) Open wp-content/themes/fudge-2/event-framework/components/shortcodes/shortcode-map.php
3) Around line number 71, you can find:
‘icon’ => get_template_directory_uri().’/assets/img/marker1.png’
4) Please change icon name in that file. And, upload the new icon to wp-content/themes/fudge-2/assets/img folder.