These are the current of the Rhinoceros Training Guides and models are in the Tutorials panel. Rhino 6, 7 & 8 have the Tutorials command that opens the Tutorials panel. To access the models that this training guide uses, there are two primary options.
The first option, Rhino will download each file when you select it from the Tutorials panel.
The second option, you may download all the files as a compressed zip and unzip them into a folder.
As a backup, if you do not have Rhino installed, you can use these links.