The video is about how to do it using other software. The software is called "Preform".
Where the video describes to assign different colors to faces, you can do that in MoI by assigning the face to a different style color. Then export to .obj format and then inside preform you will be able to place different textures on faces that were assigned different styles.
There are some other programs that are focused on applying displacement textures like ZBrush or 3D Coat, you might want to look at those.
The preform would be perfect If I can use it with my machine.
but after some testing it seems my best option is the use zsurf4.
just did a test and it was perfect for what I need this time.