in reply to Reading and updating XML

Your XML seems to use namespaces. You should study XML::LibXML::XPathContext to handle them in XPath queries.
لսႽ† ᥲᥒ⚪⟊Ⴙᘓᖇ Ꮅᘓᖇ⎱ Ⴙᥲ𝇋ƙᘓᖇ

In Section Seekers of Perl Wisdom