Download and unzip the fits tool which can be found at http://code.google.com/p/fits/ (you don't need the extras.zip just the latest version of fits-X.Y.Z.zip). Make sure to unzip it into a location where the apache user can get access. Navigate to the unpacked fits folder and add executable permissions to fits.sh so the apache user can run the script. Clone this module into your drupal modules folder and enable it in drupal to activate automatic technical metadata extraction.
Navigate to Islandora > Fits Tool (admin/islandora/fits). Here you can specify the location of the fits script (on the file system) and the dsid you want to use for the technical metadata datastream.
The System path to fits processor must include "fits.sh", so it would look like: "/usr/share/fits-0.6.1/fits.sh" instead of "/usr/share/fits-0.6.1/".
If you run an ingest and you don't get any technical metadata, check to make sure the permissions on the fits folder and the fits.sh script are correct and the apache user can run the script.
Some images and audio files will cause problems during metadata extraction. These are not fatal errors, but appear to be formats the fits script can't understand. In these cases, you will get some error reporting in the technical metadata datastream that may help determine what happened.
If you ingest an object but don't get any technical metadata, you may have forgotten to update the permissions on the fits.sh script. If that is not the case, make sure your configuration points to the correct file.