update internal installation instructions

docs/installation.rst

@@ -86,7 +86,9 @@ You should now be able to successfully ``import webbpsf`` in a Python session.
 
 .. Note::
 
-   **For STScI Users Only:** Please note, we are no longer providing users at STScI a location with the required data files on the Central Storage network. Therefore, to run WebbPSF, you must download these files and tell WebbPSF where to find them using the WEBBPSF_PATH environment variable.
+   **For STScI Users Only:** Users at STScI may access the required data files from the Central Storage network. Set the following environment variables in your ``bash`` shell. (You will probably want to add this to your ``.bashrc``.) ::
+      export WEBBPSF_PATH="/grp/jwst/ote/webbpsf-data"
+      export PYSYN_CDBS="/grp/hst/cdbs"
 
 Software Requirements
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