Verify that you have python 2.7+
Download and install DEAP (https://github.com/DEAP/deap) joblib and SCOOP (https://github.com/soravux/scoop) libraries ("pip install deap", "pip install scoop", "pip install joblib").
Download the CODGAS SIR python script here (this works for non SIR too)
Install R (https://www.r-project.org/) -- CODGAS expects this to be installed in /usr/bin/R, but you can install it wherever you want if you change the path in the code.
(Optional) Download accessory scripts to use SHELX for structure solution