Since people are still asking for it, I’m trying to keep the PRT ROP for Houdini somewhat current. You’ll always find the latest version on Github:
Installation is straight forward: just download the zip from the Releases page on the repo, then unzip the .dll file into your houdini's profile dso folder. On Windows that folder is most likely somewhere like this:
If the "dso" folder does not exist yet, just create it. Then drop the PRT_RopDriver.dll in there and start Houdini. You can then create a PRT_ROPDriver ROP node in the Outputs.