Using Twig you could do something like below.

use strict;
use XML::Twig;

$file = 'test.xml';

my $twig = XML::Twig->new(
  twig_handlers => { div => \&div_handler },
  pretty_print => 'indented'
);

$twig->parsefile($file);
$twig->flush();

sub div_handler {
  my ($twig, $div)= @_;

  if($div->{'att'}->{'class'} eq "P_FM_EPG_INTRO_FIRST") {
    $div->set_tag('paragraph');
    $div->set_att(class => "PFMEPGINTROFIRST");
    $div->set_att(style => "FM_EPG_INTRO_FIRST");
  }
}
[download]

Hi mickep76,
Thanks for your reply. I am facing data loss some time while executing my script. is there any way to find the data loss.

I am using the below code.

use strict;
use warnings;

use XML::Parser;
use XML::Twig;

my $xmlfile = 'input1.xml';              # the file to parse

# initialize parser object and parse the string
my $parser = XML::Parser->new( ErrorContext => 2 );
eval { $parser->parsefile( $xmlfile ); };

# report any error that stopped parsing, or announce success
if( $@ )
{
    $@ =~ s/at \/.*?$//s;               # remove module line number
    print STDERR "\nERROR in '$xmlfile':\n$@\n";
    exit;
}


my $twig=XML::Twig->new(twig_handlers=>{
#                                        indd_document=>\&root_process
+,
#                                        div => \&div_handler,
#                                        content => \&content_handler,
                                        });
$twig->parsefile( $xmlfile);
open(FH,">output.xml") or die "cannot open output.xml: $!";
my $temp = $twig->toString;
print FH $temp;
close (FH);

$twig->purge;

#root tag "indd_document" process here
sub root_process
{
      my( $twig, $root)= @_;
      $root->set_tag( 'document');
      $root->set_atts({OutputCreationDate=>'20090510', OutputCreationT
+ime=>'00:00:00', 'xml:space'=>"preserve"});
      $root->purge;
}

#paragraph element process goes here
sub div_handler {
  my ($twig, $div)= @_;
    $div->set_tag('paragraph');
    $div->del_att('cstyID','pstyID');
    my $attval=$div->att('class');
    $attval=~s/P_//;
    $div->set_att(style => $attval);
    $attval=~s/_//g;
    $attval="P".$attval;
    $div->set_att(class =>$attval);
    $div->purge;
}

#content tag handler
sub content_handler
{
  my ($twig, $content)= @_;

  #For textbox element
  if($content->{'att'}->{'type'} eq "text")
  {
    $content->set_tag('textbox');
    $content->del_atts;
    $content->set_atts({bid=>'', aid=>'', att=>'', pgnbr=>'', pgsect=>
+'', spp=>'', spf=>'', top=>'', left=>'', height=>'', bh=>'', width=>'
+', bw=>'', colums=>'', gutter=>'', ts=>'', ls=>'', bs=>'', rs=>'', t=
+>'', l=>'', b=>'', r=>'', tit=>'', til=>'', tib=>'', tir=>'', color=>
+'', cn=>'', framewidth=>'', framecolor=>'', fcn=>'', grp=>''});
  }
  $content->purge;
}
[download]