Note that the wizard provides added functionality and explanations. The above requires root privileges. Forget about the pictures. This is it. To test, change your working directory to the installation directory which contains some example data.
Launch gocad from there.
Then filter and export this data cloud with the wizard. Reduce it to a couple of earthquakes and reimport as beach balls. First you need data in the right format. 3 depth of event in kilometers 4,5,6 strike, dip and rake in degrees 7 magnitude 8,9 longitude, latitude at which to place beach ball. Entries in these columns are necessary with the -C option.