Use https://svn.ozone.ri.cmu.edu/r as the base URL. Do not checkout this URL directly, however, because the result will be extremely large.
Most likely you will check-out the trunk:
svn checkout https://svn.ozone.ri.cmu.edu/r/trunk
Or switch an existing working copy to it:
svn switch --relocate OLD https://svn.ozone.ri.cmu.edu/r/trunk
where OLD is your current URL and can be obtained from svn info.
TortoiseSVN provides a Relocate command which operates similarly.
The new repository uses SSL encryption. Details on the certificate can be obtained Here.
Password change form is Here.