how to ignore namespaces with XPath
You can use the local-name() XPath function. Instead of selecting a node like
/path/to/x:somenode
you can select all nodes and filter for the one with the correct local name:
/path/to/*[local-name() = 'somenode']
You can do the same In XPath2.0 in a less verbose syntax:
/path/to/*:somenode