Resolution:
The following are the steps necessary to change the Administration Tool port on a GridServer installation.

   1. Log in to the GridServer Administration Tool.
   2. Click the Admin tab. click Manager Reconfigure, then click Manager Configuration.
   3. Go through the screens until you see the "Web Administration" section
   4. Change the port number.
   5. Continue through the screens and click the Start Installation button.
   6. When the Manager is done reconfiguring and has shut down, edit the conf/resin.conf file. Under the comment:

      <!- The http port ->

      Duplicate the following line and alter the port number to the one specified in the Web Administration section above.

      &lthttp server-id="" host="*" port="8420" />

   7. Save and close the resin.conf file and start the Manager.