I cannot find a good/official way to do this in Ubuntu.
The best one I got from googling is this post.
So how can we completely remove UberSVN after installing it?
Yes, it's not installed via the package manager, so it's going to need you to do two things to uninstall uberSVN completely (it would be good to know why you want to uninstall too?).
That will remove all traces of uberSVN...
Also, as root edit these files and remove the uber* user and group: