There are only two steps to follow; from your Un*x shell prompt:
That should be all that is needed. If you have any problems (remember, SATAN is currently only fully supported on SunOS 4.x and IRIX 5.x, although this will change by the final release), you should read the full documentation on configuration and installation.
You should now go to Scanning your host or networks to see how to start scanning hosts using SATAN.