Please be aware that Dustin's wiki you linked to is just mirroring the installation information - the source for the PyPRP plugin (and where it will be updated when anything changes) is at
http://www.guildofwriters.com/wiki/Installing_PyPRPI'll add the link to the video do that page

EDIT: Also, Ages Beyond Myst does *not* suffice for age creation. PyPRP and the Offline KI require the Path of the Shell expansion pack.
And the UAM KI Plugin is currently optional, no age is using it yet. Required for age building is only the Offline KI (unless you are using some other tool to reach your ages). The files of the AgeInformation package are contained in the Offline KI, but it's still a good idea to install the separate package as it is intended to release updates without making a full Offline KI release.