The information on this page is outdated and not particularly relevent anymore, but it may be useful to those who still have older (pre-2014) SSB installations in /usr/stsci.
Installing CDBS locally on a Mac
If you're on the STScI internal network, you can use the CDBS on the Central Store (in /grp/hst/cdbs).
If you have a Mac laptop, you may want to install a local copy of CDBS data from the CDBS package. The data will be installed into /usr/stsci/stdata. The CDBS package can be downloaded from http://stsdas.stsci.edu/fetch/cdbs.dmg or accessed directly from the Central Store (/grp/software/osx/cdbs.dmg).
You specify where the CDBS data is by setting the environment variable $crrefer. This is IRAF, so remember to put a "/" at the end of the directory name.
Removing software installed by old DMGs
There is a Macintosh package that will remove the material installed by the old DMG files (in /usr/stsci). You have to "install" it to make it remove the old software. It is available here. You should only need to run this once.