Note, I closed your suite for you.
use strictures;
use XML::LibXML;
my $before = <<"";
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE suite SYSTEM "http://testng.org/testng-1.0.dtd">
<suite name="Automation Suite" verbose="1" parallel="false">
<test name="Configuration Restore Test Suite">
<classes>
<class name="com.qa.testsuite.ConfigurationRestoreTests" />
</classes>
</test>
<test name="Import Test Suite">
<classes>
<class name="com.qa.testsuite.ImportTests" />
</classes>
</test>
</suite>
my $doc = XML::LibXML->new->load_xml( string => $before );
my ( $test_suite ) = $doc->findnodes('/suite/test[@name="Import Test S
+uite"]');
$doc->setDocumentElement( $test_suite );
print $doc->serialize; # or $doc->toFile(...)
This may or may not be sane given the DTD but it gives the output you want. Update, there is a toFile() method for the doc.