Let's try to keep this as short as possible.

1. Content > Content Manager > Video on Demand >> Click + Add new Video on Demand

2.  Fill in all the information.

3. Upload your video and thumbnail. Add subtitles if you'd like.

4. Insert Images for your video post. And crop them to fit the different sizes for the different devices. (PC, Tablet, Cell)

5. Add cast members if you'd like.

And voila! You're all set.