The Extended Greek Mod-Extended Cultures is a fully mod-foldered modification for RTW 1.5, BI 1.6 or Alexander, and will not interfere with other mods.
To install Extended Cultures, first make sure your version of RTW is fully patched, then download the latest version of Extended Cultures. Run the simple, easy to follow installer, which should detect your RTW folder automatically. The installer will install all of the files to the folder "xc" which it will create. Finally, run the game through the Extended Cultures shortcut that was also installed, and you are good to go.
You can get the latest version here.
You can look at the read-me here.
Also, if you enjoy Extended Cultures, please consider donating to help pay for hosting costs. You can donate on this page.