The seismic SVN repository has been moved to Kerberos access control, with the new location being: https://svn.ligo.caltech.edu/svn/seismic.  (The previous site was https://svn-private.ligo.caltech.edu/repositories/seismic)

Instead of wiping away the old directory and checking out the entire new one, I simply switched the site the SVN uses to update its local copy.  I switched the site for the LHO CDS "controls" account (in the control room) and the X1 SEI Workstation copies.

On the X1 SEI workstation, the repository local path is still the same:
'/opt/svncommon/seisvn/seismic/HAM-ISI/'

And in the Control Room, the "controls" user copy is still located at:
'/hanford2/users/controls/isi_local_files/SVN/seismic/HAM-ISI/'

New user names and passwords are the LIGO.ORG ones.  

On the workstation, here's the command I entered to switch the checkout site:

>> svn switch --relocate https://svn-private.ligo.caltech.edu/repositories/seismic/HAM-ISI/ https://svn.ligo.caltech.edu/svn/seismic/HAM-ISI/ --username jeffrey.garcia@LIGO.ORG

*entered in the '~/seismic/HAM-ISI/' directory.