To download and use the SWAP model you will first need a copy of NetLogo installed on your computer. To download NetLogo, go to https://ccl.northwestern.edu/netlogo/ and follow the instructions.
Once you have NetLogo installed, simply download the SWAP model by going to – http://modelingcommons.org/browse/one_model/4117. And selecting ‘Download this model’ (just below the image of the model). Open the .nlogo file – this should open in NetLogo automatically, if not, open NetLogo and open the file from there.