Sorry for the three big Odysseys I just have written down below, I usually elongate it a little bit and Steam comments section have a stupid 1000 character limit. Seems that every social media today don't want to people get used to read much...
Start for the lowest comment I written at this comment section.
Thanks for your appreciation and attention and I wish you a wonderful night, my friend! :)

For now, if you want start modding, I would recommend you to download a good sound editor (I prefer Vegas as I use it for a long time, but there are a lot free ,easier and better programs than this one), a audio converter (you can do this at some online converting sites you find on web. You will need it to convert to mp3, wav and ogg and to allow you to change - usually you will not need to do it, but, for precaution - some properties of the file like frequency - Insurgency sounds need to be at 44100 Hz) and Insurgency SDK installed (download it by clicking right button at Insurgency name at Steam Library>Properties>Additional Content and selecting Insurgency SDK. It will download automatically from this point). If you think you can't really do it, I will make a exception and do this mod for you, but don't expect me to do it very fast :/
Thank you for appreaciating the mod and have a great night, sir :)

(Note: If you learn how to mod in Insurgency, you will be capable of doing it for any other Source game ,like L4D2 and Garry's, just with some adaptations)
Still, if you have a problem with it, or, maybe, want me to teach you (if you download the proper tools and follow some of my tips, it will be no trouble for me and my time schedule doing it, and, after all, this would be better for you - as you wouldn't ever need other people to do mods you like, and having the problem of the person you asked delay it so much or doing the work bad - and for the community - one more modder for us. Yayyy!!!!!) you can add me as friend and call me at any moment (I usually log in steam once a day to check my mod messages, surely there will be a time that both of us will be online and I can help you).

Hm, it certainly can be made but, sadly, I'm not doing mods anymore :(
For this specific music ,I really would want to do it, but I usually had in my older computer a folder with all the things needed to do it (like sound files names and folder patches inside the game directory) and the tools needed to (Sony Vegas, good audio converting tools, Insurgency downloaded - needed for uploading the mod and for packing it [ vpk.exe ]) , and now ,to do it properly, I would have to download all this again and I think it would be a lot of trouble, mainly for my lack of time and for the slow internet connection I have now. But, if you want, you could learn how to do it and do, not only this mod, but any you want. This guide here teaches pretty good how to do it, and, if you want, you can find a lot of topics at community discussions solving common problems and teaching in other ways as well:
https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?l=portuguese&id=349559876

Can this be made for last man standing??

Nice!! i didnt saw this one, it fits perfect ,viva la revolución!

Check this skin out that my friend made for me https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=379146058

This name: <3

Lol fuck yeah immortal tech