All files you need for this analysis are available here. Please see the documentation for the use.
The files are archived, so they have to be decompressed as described in Section 2 of the documentation. Move files as you wish after it is decompressed so that you can work with them easily.
All of source code files have comment lines to help you understand what you are doing. So read them while some of the script are running for long time! There also is a web page which holds list of commands used in these scripts. Of course, ArcInfo's well written on-line documentation (accessible with help command at Arc: prompt. Need X Window system) is a better source of info...