Installation is a two step process from the main demo download WEB page:
Execute the unified PolyTrans/NuGraf demo installer. This will allow you to install either the stand-alone NuGraf or PolyTrans program. You can install either one. NuGraf is a more full featured version of PolyTrans, as described here.
Execute the 'Okino Plug-ins Super Installer' which allows you to download and install the native
plug-in systems for Maya, 3ds max and Softimage.
Instructions on how to execute the PolyTrans-for-Maya plug-in system are described on the demo downloads WEB page, as well as in the 'ptio_maya_install.txt' file which will be presented to you after installation is complete and which will be copied into the Maya 'bin\plug-ins' directory.