Download it from here.
I save my files to a simple “GTA V mods” folder to keep everything organized.
Once you have the file saved, extract its contents into a new folder.
You then need to drag the pertinent files into the GTA V file folder.
That folder will typically look something like: c:program files (x86)SteamSteamAppscommonGrand Theft Auto V.
If you see GTAV.exe and bink2w64.dll, you’re in the right spot.
For the FOV mod, this means I need to drag fov.ini and dsound.dll into Grand Theft Auto V folder.
You can then adjust the variables in fov.ini to get exactly the field of view that you desire.
Boot up GTA V, and you’re good to go.