sorry but this is not available by default.
I had to deal with the same problem and I solved it via database. It is enough just to run the script:
UPDATE jfq4_em_events SET recurrence_id=0 WHERE recurrence_id>0
UPDATE jfq4_postmeta SET meta_value=0 WHERE meta_key=”_recurrence_id” AND meta_value>0
The script is based on the code of detach function.
/**
* Returns if this is an individual event and is not recurring or a recurrence
* @return boolean
*/
function detach(){
global $wpdb;
if( $this->is_recurrence() && !$this->is_recurring() && $this->can_manage('edit_recurring_events','edit_others_recurring_events') ){
//remove recurrence id from post meta and index table
$url = $this->get_attach_url($this->recurrence_id);
$wpdb->update(EM_EVENTS_TABLE, array('recurrence_id'=>0), array('event_id' => $this->event_id));
update_post_meta($this->post_id, '_recurrence_id', 0);
$this->feedback_message = __('Event detached.','events-manager') . ' <a href="'.$url.'">'.__('Undo','events-manager').'</a>';
$this->recurrence_id = 0;
return true;
}
$this->add_error(__('Event could not be detached.','events-manager'));
return false;
}