Hello Jome Akpoduado,
Thank you for using our services.
This webinar relates to an older version of Sitefinity and the RadControls for ASP.NET AJAX. Since then we have moved to using embedded skins for the RadControls. This is why you are not able to find the folders Gabe is talking about. In order to gain access to the orginal skins you can download a trial of the RadControls for the ASP.NET AJAX, then use the skins from there. Please, take a look at this KB article
for more information on how to style the RadControls for ASP.NET AJAX in the latest versions of Sitefinity.
the Telerik team