Drag or paste sharedassets1.assets-mod into

C:\SteamLibrary\steamapps\common\Phasmophobia\Phasmophobia_Data

Make a copy of the original archive just in case renaming it with something like 
"sharedassets1.assets-original".

Remove the "-mod" part of the archive.

Enjoy the Jojo's references and have a bizarre ghost hunt.

Credits:
Idea and modification: NoobTriesToWin
Texture edit: ACasualOnion

You can find both of us in the next Youtube channel:
https://www.youtube.com/@acasualonion