[8FS_Bulau]

If all I wanted were then to activate the use of one mod, would you know what files I need to download, install or replace?

The sound MOD would be the absolute minimum files needed to use just one MOD

There is also the Mod Activator v 5.2, which give you a Modded, (moddable) game, but without the new sounds:

(The link is inoperative)

After installing that, you should be able to install an additional single mod, however, SOME single mods may depend on other Mods for bits and pieces. I would make a copy of your 4.08m install, rename it, then mod that, in case things go wrong. Cheap insurance!