Jason Wong on "[Plugin: WooCommerce] How to make Custom fields displayed in Admin Order editable?"

Yahoo! I managed to get it to what I want, as shown here, with the following codes.

// Extra Shipping fields
function wc_extra_shipping_fields( $fields ) {

        $fields['shipping_email'] = array(
                'label'       => __( 'Email Address', 'woocommerce' ),
                'required'    => true,
        //      'placeholder' => _x( 'Email', 'placeholder', 'woocommerce' ),
                'class'       => array( 'form-row-first' ),
                'validate'    => array( 'email' )
        );

        $fields['shipping_phone'] = array(
                'label'       => __( 'Phone', 'woocommerce' ),
                'required'    => true,
        //      'placeholder' => _x( 'Phone', 'placeholder', 'woocommerce' ),
                'class'       => array( 'form-row-last' ),
                'validate'    => array( 'phone' ),
                'clear'       => true
        );

        retu $fields;
}
add_filter( 'woocommerce_shipping_fields' , 'wc_extra_shipping_fields' );

// Extra Shipping fields in Admin Order Meta
function wc_extra_admin_shipping_fields( $fields ) {

        global $theorder;

        $fields['email'] = array(
                'label'       => __( 'Email', 'woocommerce' ),
                'value'       => get_post_meta( $theorder->id, '_shipping_email', true ),
                'validate'    => array( 'phone' ),
        );
        $fields['phone'] = array(
                'label'       => __( 'Phone', 'woocommerce' ),
                'value'       => get_post_meta( $theorder->id, '_shipping_phone', true ),
                'validate'    => array( 'phone' ),
                'clear'       => true
        );

        retu $fields;
}
add_filter( 'woocommerce_admin_shipping_fields', 'wc_extra_admin_shipping_fields' );

I just hope nothing is amiss ... (--)"