What you will need:

- .WAV File of custom music or sound*
- GCFScape Software

*For some files, you will need an .OGG File of your custom music or sound as well~

-Download GCFScape from
http://nemesis.thewavelength.net/?p=26
This tool is used for opening VPK files

-You can convert between .MP3, .OGG, and .WAV files using audio editing software or online converters

-Some files are REQUIRED to be a mono, not stereo track in order to work properly, such as the weapon handling sounds.

Before we start making our custom music, we need to know the names and locations of the original files that we want to replace. Here's how to do that:

Locate
C:\Program Files (x86)\Steam\SteamApps\common\insurgency2\insurgency

Open
insurgency_sound_dir.vpk using GCFScape.
It should look something like this:
*Note: You may have to close Steam and run GCFScape as administrator in order for it to work.

Navigate
through the VPK archive using the file trees on the left.

Find
the music file we want to customize.
You will notice that the sounds are organized into a fairly intuitive file system.

For example, files for the main menu music can be found in
root\sound\music\mainmenu
while files for the ak47 sounds can be found in
root\sound\weapons\ak47

By right clicking on a music file, we can extract and listen to it to hear exactly what sound it is.
I cannot list what each and every file is so you can find out for yourself.
If you wish, you can extract the entire insurgency_sound_dir.vpk for easier navigation.

Remember
the name and directory of that file.

For example the Counterattack music of Co-op vs AI will be in
root\sound\cues
and the file names will be
ins_gamemusic_abouttoattack_a.wav
ins_gamemusic_abouttoattack_a.ogg


Now that we know the file name and directory, onwards to mod creation! ^_^

Make
a new folder directory with the same names of the directory that we remembered from earlier.

For example of the Counterattack music from Co-op vs AI, I would create a new folder called 'root', create a new folder in it called 'sound', and then create a new folder in that folder called 'cues' to end up with:
root\sound\cues

Place
your custom .WAV and .OGG music files within the directory you just made.

Note: The latest patch requires sound mods affecting radial or bot vocalizations to be in the following format per this announcement : OGG Vorbis, VBR, Quality: 1.00, Sample Rate: 44,100Hz, Channels: Mono.

Rename
your custom .WAV and .OGG music files to the name of the file we remembered from earlier.

For example of the Counterattack music from Co-op vs AI, I would rename the files to:
ins_gamemusic_abouttoattack_a.wav
ins_gamemusic_abouttoattack_a.ogg

If you have successfully followed these steps, you should end up with a folder like this:



Drag
the entire folder onto vpk.exe located in:
C:\Program Files (x86)\Steam\SteamApps\common\insurgency2\bin

shown here:
This will copy and convert the folder into a .VPK file

Move
The newly created .VPK file to:
C:\Program Files (x86)\Steam\SteamApps\common\insurgency2\insurgency\custom
shown here:

This will automatically apply your sound mod to your Insurgency game.
Feel free to rename the file to something practical.

Enjoy
your new custom sounds! Congratulations, and thank you for reading this tutorial! ^ω^

Not only do I like sharing mods with the community, I also find that I have a higher success rate of getting my private mods to work when I upload them to the workshop and subscribe to them myself. If I don't want to share it, I can keep the hidden visibility setting so that no one else can see them except for me~ Here's how to do that:

From the Insurgency Main Menu, Click on the Workshop tab on the top right:
If the tags don't show up, spam the Upload tab on the top right~

Press the Browse button to choose the mod file you want to upload:

Give a title and description for you mod, check the appropriate tags, and upload a nice thumbnail image for it:

You are now ready to publish!

The workshop page for your mod should show up if it successfully uploads:

You can scroll down and choose the privacy settings for your mod as well as edit other details~

-To share your custom sound mod with the friends and the steam community, simply upload your .VPK file to the workshop~



-Some sound mods may not take effect directly after applying it. If you are not hearing your custom sounds, try opening Insurgency's console and entering the command: snd_restart