You can download them using the links in the blog posts.
but in the following link:
http://blogs.kent.ac.uk/mik/tag/class/
in blog #17 i dont see any links?
isn't it possible to download the pictures he uses for the classes ?
That entry shows the creation of a scenario from scratch, so there is nothing to download. The pictures are in the Greenfoot images library, in the "symbols" category. If you watch the video and do exactly as Mik does, you will see them.