use warnings;
use strict;
use XML::LibXML;

my $doc = XML::LibXML->load_xml(location => 'foo.xml');
my @nodes = $doc->findnodes('//param[@name="SSLKeyStorePassword"]');
if (@nodes) {
	warn "found more than one SSLKeyStorePassword" if @nodes>1;
	$nodes[0]->{value} = 'BLABLA8';
}
else { die "did not find SSLKeyStorePassword" }
$doc->toFile('bar.xml', 1);