I had a look, and it IS a WordPress site.
To embed a video you will need a plugin called Embedly. That has to be installed and activated. Then you have to select YouTube in the 'services' area of Embedly. In the page where the video is supposed to appear, you paste the URL of the video.

BTW, you or your friend has to be registered at Embed.ly to obtain a key. Without that key it won't work. It doesn't cost anything unless you need masses of URLs.

Ok thank you Inger, i'll let him know