Make sure to first have SuperBLT, and CustomOST installed. Click the links in the dependency list.

Optional video tutorial for installing SuperBLT, BeardLib, and mod_overrides mods: https://youtu.be/rin_sjSJIkg

1. After downloading the mod, use a program such as 7zip or WinRAR to extract the main folder of the mod.
2. Navigate to mods\CustomOSTTracks. The mods folder is supposed to be in your game's installation folder (don't know where that is? click here).
3. Move the main folder of the mod from step 1 to the folder you navigated to in step 2.

Make sure to first have SuperBLT, and CustomOST installed. Click the links in the dependency list.

Optional video tutorial for installing SuperBLT, BeardLib, and mod_overrides mods: https://youtu.be/rin_sjSJIkg

After downloading the mod, use a program such as 7zip or WinRAR to extract the main folder of the mod.
Navigate to mods\CustomOSTTracks. The mods folder is supposed to be in your game's installation folder (don't know where that is? click here).
Move the main folder of the mod from step 1 to the folder you navigated to in step 2.
If you're familiar with Payday 2 sound mods and already have CustomOST setup, drag and drop the folder inside the Zip/Rar file into your CustomOSTTracks folder.

Otherwise, I recommend going through this mod pages description and following the steps (It says it may be outdated, but I still use it as of making this post).