use strict;
use warnings;

use XML::Twig qw( );

binmode STDOUT;

my $t = XML::Twig->new(
   twig_handlers => {
      '/Profile/Application' => sub {
         my $Id = $_->att('Id');
         my $CsID = (split(/\//, $Id))[-1];
         $_->set_att(Id => $CsID);
      },
   },
);
$t->parsefile($ARGV[0]);
$t->flush();

##</code><code>##

use strict;
use warnings;

use XML::LibXML               qw( );
use XML::LibXML::XPathContext qw( );

my $doc  = XML::LibXML->new()->parse_file($ARGV[0]);
my $root = $doc->documentElement();

my $xpc = XML::LibXML::XPathContext->new();
$xpc->registerNs(x => 'xxxxxxxxx');

for ($xpc->findnodes('/x:Profile/x:Application', $root)) {
   my $Id = $_->getAttribute('Id');
   my $CsID = (split(/\//, $Id))[-1];
   $_->setAttribute(Id => $CsID);
}

binmode STDOUT;
print $doc->toString();