I’ve just started to try to edit the templates. It’s not quite as easy as Blogger, as by default the ability to edit files is disabled.
In order to do it, you have to first of all make the files writeable. I managed to do it for one file using SSH shell – which is on the University system, and that page gives links to instructions for other FTP Clients (CoreFTP is the one that the Uni Wireless team recommend for secure FTP, though I prefer FileZilla)
I’ve made 1 file writeable, I’m not sure if I can do the whole directory, or if I have to do them one at a time. Still, the latter is safer.