Made by my friend over at: https://github.com/12brendon34/DLML

1. Drag dsound.dll in your Dying Light directory.
2. Create a folder named "CustomPaks" in your Dying Light directory.
3. Move datapaks that you want to play with in multiplayer in that folder.

After doing all those 3 steps, you can play the game with mods.

You can also press F5 and see game's logs in real-time.