If you have never change anything in an Ageod game but you want to, i will tell you imo what is the easiest thing to start with.
Change an event
what you need?
The original excel file from AGEOD DDBB.
The tool CSVSplitter.
Read the Ageod wikipedia in order to use properly the Ageod script commands (this is the main difficulty here).
To have clear what you want to change/add.
You can find the tools here http://www.ageod-forum.com/showthread.php?5358-Official-Files-for-modding
And the AGE-Wikipedia here talks about scripts commands.
You want to add a new unit in an event of AACW.
Open the excel file AACW_inc_CSA_MilitiaReactions02b.xls
Add a new line copy of a previous one. In Red what i have changed.
save the file.
Save as--->Other Formats------>CSV separatted by commas
sorry, my excel is in spanish.
Now you have to convert this csv file to the correct script file.
And select the tab the arrow marks. Choose the correct input file and output folder (the ones you use to work with)
click convert. This creates the script file in your output folder.
We now have our script file Emergency_CSA_Militias
take this file and copy it into your AACW events folder.
Play the game and you will see when the event is fired that a new unit appears!