In order to rename a repository you only have to rename its root directory and generate a new UUID. Assuming the repository is in /var/svnroot/my_repo you have to run this commands (as root) to rename a repository:
$ mv /var/svnroot/my_repo /var/svnroot/my_new_repo
$ svnadmin setuuid /var/svnroot/my_new_repo
After that, you can access it through your favorite protocol.