Nuclear Control Add-on - How to add sounds for the howler alarm without tekkit or ftb

Hello!
I have recently downloaded IC2, Buildcraft, Railcraft and Forestry. Building a little town I now wanted to use the howler alarm from the nuclear control add-on as a siren to alarm the volunteer fire brigade (in Germany this is still quite common). Also for new buildings it would be cool, not just to use note blocks, but the German standard fire alarm (which I think sounds the best) I've heard from the possibility of adding sounds on different mod presentations and when I typed it into Google I got lots of results... But only for the tekkit and Fed-The-Beast modpacks (which I don't have). Nowhere any information how to do it without. I've checked my whole .minecraft-folder but I didn't find anything.

So how can I add sounds for the howler alarm only having installed IC2 with the Nuclear Control Add-on?

I was thinking it doesn't require ftb or anything else, but an assets-folder containing a nuclearcontrol-folder DOES *?"()§)/"§=&$ NOT exist in the .minecraft folder. In all the tutorials this assets-folder is found ONLY in a .tekkit- or ftb-folder which I, of course, don't have on my computer. I also never got a .zip folder for the mod, only a .jar file.

Ok, found it. I have now converted my alarm sound to an .ogg-file and named it "alarm-...". When I now try to copy it to the sounds file using 7-zip it says "This folder does not suport this action." WHat shall I do now?

I don't know if my translation is accurate: In German it says: "Dieser Ordner unterstützt diese Operation nicht." Perhaps it can also be translated with: "THis folder does not support this operation." I've also tried to edit the .jar-file in the downloads folder and then to copy it, but I also can't copy the sound into the folder there. I've also tried to unzip the folder and copy the sound in there, but it didn't work. Also Running 7-zip as administrator didn't change anything.


+ =

Hello? Is there anybody? In case anyone thought it: This is not yet resolved...