#!/usr/bin/env perl

use warnings;
use strict;

use XML::LibXML;

my $file = shift || die "usage $0 <xmlfile>\n";

my $parser = XML::LibXML->new();
my $dom    = $parser->parse_file( $file );
my $doc    = $dom->documentElement();

my @rules  = $doc->findnodes( '/policy/policyrules/Rule' );
my $parent = $rules[0]->parentNode->parentNode;
   $parent->removeChildNodes();
   $parent->appendChild( $_ ) foreach @rules;

print $dom->toString(1);