You can create a batch file to launch the game with the mod - there are other ways but this is simplest for me:
1) create a new text file
2) In Notepad, copy/paste the following into the text file:
Code:
Empire.exe mod patch_aum_en_loc.pack; mod aum_mod.pack;
NOTE: the filenames will be different if you are using another version of the mod - i.e. one designed for use with another mod, or another language. My own is for APE:TI, and looks like this:
Code:
Empire.exe mod patch_aum_en_loc_ape_ti.pack; mod aum_mod_ape_ti.pack;
(I didn't include the APE:TI files, but they're there as well, in order to run both mods at once).
NOTE 2: I only have the two files...so I don't know what to do with the third you mention, or why you would need it.
3) Click File > Save As, and name the file AUM.bat (the first part isn't important - but the .txt must be changed to .bat)
4) Place this batch file into your Empire Total War directory (Program Files\Steam\Steamapps\common\empire total war) and run it directly, or create a shortcut to it on the desktop to make it easier.