Use OpenIV to navigate to GTA V/x64/audio/sfx/RESIDENT.rpf
Then right click vehicles.awc and click export to openFormats.
Export to your desktop then you will see a vehicles folder and a vehicles.oac file.
Export the 0x1AE3EF45.wav file you downloaded to the vehicles folder and it
automatically updates the vehicles.oac file.
Then all you have to do is drag the vehicles.oac file to the RESIDENT.rpf file and it will automatically revert to vehicles.awc
This replaces the Sad Trombone Horn so you have to add the Sad Trombone horn to
your vehicle for it to work.

First upload! Thanks!!

Creds to MisterY for telling me how to change!