\Steam\steamapps\common\Call to Arms\mods. Many of the files within the PAKs are simple JSON-like text files and easily edited. Or if you prefer, copy the files to a working folder, change the file extension to zip, and extract them.
These are simply ZIP files, and you can view or extract them with your favorite ZIP app.
Data files that control a large number of game properties are typically found in the following folder: \Program Files (x86)\Steam\steamapps\common\Call to Arms\resource\.
