Just remember an engine cant work on its own. You need an interface. like Scid or Arena too.
How to Download An Engine

Someone (not me-I suck at computers) could probably give you the steps if they knew what GUI you were downloading the engine into. Downloading is easy; it's the finding the file, the unzipping, the finding the unzipped file and the moving it into the GUI that's challenging. I moved Houdini 1.5a into Fritz 12 a few years ago but for the life of me I don't remember the steps.

LOL just because your dad is a programmer doesn't mean he will understand it. you need an engine and a gui.
for an engine i reccomend Stockfish DD. it is the second strongest chess engine, it is opensource and free
http://stockfishchess.org/download/
for a GUI i reccomend arena its free and i find it a little more intuitive than the other free GUIs
http://www.playwitharena.com/?Download:Arena_3.5

It would be a matter of 5 minutes for him. Do you have anything now or are you starting from scratch? As Rooperi mentioned an engine doesn't work on its' own any more than a car engine does. Commercial programs are available and not super expensive but there are lots of good free GUIs and engines available for download onsite (the last item in More; that green bar at the top?). Do a search forums (the rectangle in the upper right) for best free engine and best free GUI. Once you read a few threads you'll have a better idea of what you want and then your dad can help you download it and set it up. Good luck!
How do you download an engine like Stockfish, Houdini, etc? I find some are free but the steps are actually really complicated. Can someone please help? Thanks.