The files are just in the SVN. Any updates would have to be manually pushed to the site (i.e., I would download the updates from the SVN locally, check them over to make sure they make sense and are correct, and then I would manually upload them to the site). The SVN tracks revision authors and dates, and lets you easily undo changes and revert to a previous revision. So, go ahead and hack away, even if you don't really know what your doing. It's just a bunch of HTML files really. Besides, no one else will even see it unless you commit the changes, so you can always at least try stuff locally and see how it goes. If you don't like the changes, or they failed horribly, you can just delete your local copy, and nobody will ever know.