This release requires Zope 2.4.x and later. You also need PyXML 0.7.x or later installed, or at least a recent version of pyexpat.
Unpack the ParsedXML tarball in the Products directory of your Zope installation (usually this is lib/python/Products). Rename the unpacked directory to "ParsedXML" so that Python can import it.
Restart Zope. There should be a ParsedXML product in your Products folder, and a ParsedXML option for available objects to add in the root folder.