what are you wanting to do, exactly?
The big thing with SR is that it uses a cache file to compile a bunch of the files needed to run the game. One of these files is the Unit.OOB file--the one with the unit data. Once you make a change in that file, you have to remove/rename the game file (in the Cache folder). The program will then "re-cache" the game on the first time it runs (it seems like the game locks up; it isn't, but caching can take a bit). Once it is done, the game goes back to the main menu. Exit the game, find the save game folder (in Win 7, it will be located under C:\Users\ [the user name]\My Documents\My Games\Supreme Ruler Cold War.
Go visit http://www.supremewiki.com/
. It has the best updated info on how to mod the game. It will walk you through the process.