I too was getting the re-declare error. What I ended up doing is inserting this right before the function in the functions.php of my child theme:
remove_action(‘vczoom_meeting_before_shortcode’, ‘video_conference_zoom_shortcode_table’, 10);
add_action(‘vczoom_meeting_before_shortcode’, ‘video_conference_zoom_shortcode_table_styled’, 10);
So basically removed it, then re-added it, then the modified function.
Seems to work now.