Help downloading graphics mod

[metamike]

I have Civ III PTW, with the latest patch, and am a so called "noob" in everything technological. I cannot seem to find out how to "unzip" my downloaded Graphic Files that pop up in WinRar, and how I'm supposed to over-write them on my previous art files.

If possible, I would be very relieved if someone might post some instructions as ways for me to do this .

P.S. : Yes, because I have PTW I automatically have them on my game, but they only work for the "New Game" option, and I would highly like to create my own scenario and play it with those beautiful surroundings.


Thank you in advance, ~~(Insert name here)