That's true, but I think he means how do you get to it to "load" it. I had the same problem, thinking it has to do with "Add something" menu option. It doesn't. It's under File -> Insert Clip File, then wherever you saved it. Then, find the last node labeled Sand Grain Sparkle, [in the node network under Terrain] and connect the output to the default Compute Terrain input. [NOT Compute Terrain_1]. There nice dunes.
Otherwise, I feel for you. I'm waiting for better dcumentation, too, but in the meantime, have at the many fine tutorials here and have a blast experimenting!