Well, what I'd do first is:
Check the file for viruses.
Then, I'd unzip or unrar into a folder on my desktop and look for a README, HOWTO or INSTALL documentation.
Copy or move the files to the proper directory as indicated in the README, HOWTO or INSTALL documentation.

I've never used Ruby but I do program in Python. They pretty much go hand in hand and work in much the same way.

A Ruby script is going to be a Ruby program. It will be expecting a Ruby command interpreter to be available - most likely in your path. If you have other Ruby scripts already running then it should only be a matter of putting it in the right place and resolving any other dependencies. The README or HOWTO file that should be included with the script should be able to help with any dependencies.

Hope this helps.

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Codifex
1981 240D ChinaBlue (Got her running with a donor engine.)
1983 300DTurbo w/sunroof.
1984 300TD manual sunroof. (Electrical Gremlins)