Step by step how to buy videos:

Step 1:

Fore buy video's from 26/04 to 06/05:

Go to: https://vimeo.com/ondemand/jumpinglummen/

Fore buy video's from 07/05 and 09/05 to 14/05:

Go to: https://vimeo.com/ondemand/weekdrie/

Step 2:

Enter the name of the rider in the upper right corner of the vimeo website and click on search.

Step 3:

On the next window select Videos, such as below.

You now see all your videos and you can buy them or rent for 24 h.

Thanks Jumping Lummen.