You need to unpack Soundfiles from the Game, to have access to the Files you wanna change.
Sounds (Common) Board
see the first Stickied Articles, it says PRS files and SFS Files next to Buttons.
Handling the 3 tasks we have Tutorials how to's here on SAS.
First is to find a Tool to open Buttons, to get a clue about FMs and EMs where you get the names for PRS Files stored in Sound.SFS Files.
These you can open like an archive with a SFS Tool. We have several.
Sound Files exist for Stock Game and in BAT Files.
Unpack both and store logically, at every custom Modding, getting access to these core Sound Files is necessary.
They build the base for your task.
I think this is the first Cliffhanger for Beginners, but once you tackled that wall, the rest comes easy.
Just be resilient, crying does not help, shortcomings, they mean nothing.
Everybody can mod, do such custom changes. Generations of Users did before.
Having a custom Sound Mod, you see the core, it's nice, but the endproduct of what you wanna do.
Don't concentrate on the result, but the lil steps needed to get access to what's hidden before your eyes.
The Soundfiles, their structures. If you don't have access to the Soundfiles, a custom Mod won't help.