Here is the last of the world Machine Basics series of videos. This one covers how to set up and export your world Machine terrain.
You can download the World Machine file here: https://www.dropbox.com/s/8zgadkimnhvkx9t/Presentation%20-%20Export.tmd?dl=0
The next video will look at how to use the exported files in Photoshop (or GIMP).