How to make remarks , date, time , location , status optional.

Note: Copy and paste it in functions.php of your current theme.

add_filter( 'wpcargo_history_fields', 'wpcargo_history_fields_callback' );
function wpcargo_history_fields_callback( $history_fields ){
    /*
    	Make the fields unrequired
    */
    $history_fields['date']['required'] = false;
    $history_fields['time']['required'] = false;
    $history_fields['location']['required'] = false;
    $history_fields['status']['required'] = false;
    $history_fields['updated-name']['required'] = false;
    $history_fields['remarks']['required'] = false;
    /* 
		Renaming the fields
    */
    $history_fields['date']['label'] = 'Date New Label';
    $history_fields['time']['label'] = 'Time New Label';
    $history_fields['location']['label'] = 'Location New Label';
    $history_fields['status']['label'] = 'Status New Label';
    $history_fields['updated-name']['label'] = 'Update Name New Label';
    $history_fields['remarks']['label'] = 'Remarks New Label';

How to make remarks , date, time , location , status removed.

    /* 
    	Removing of fields 
    */
    // Remove Date
    unset( $history_fields['date'] );
    // Remove Time
    unset( $history_fields['time'] );    
    // Remove Location
    unset( $history_fields['location'] );
    // Remove Status
    unset( $history_fields['status'] );
    // Remove Update Name
    unset( $history_fields['updated-name'] );
    // Remove Remarks
    unset( $history_fields['remarks'] );

    return $history_fields;
}