Hi and welcome,
If you go to the VIP section - you will see all the videos available to download - Each one has a certain amount of points allocated to it, and some are done over two or more individual video's (Like say 'Texturing Part 1, Texturing part 2' etc) So once you decide what you want, and how many points you need to purchase the video(s). You go to the "Buy points" section and purchase the points from there.
After that - go back to the VIP section and download what you need.
Hope that explains what you needed to know.