1. Your Mod Journey Starts Here
The screenshot below is what your GTA 5 folder structure will be after your first game install. You will have roughly 44 items (files and folders) in the installation folder. We will also refer to this folder, where GTA5.exe is located, as the root folder or the game folder. Click on the picture below for full size.
If you don't know how to find the GTA 5 folder, which might be called Grand Theft Auto V, you can read this article on our sister site called How to find GTA5.exe.
We will start by installing a free program called Open IV. It is likely pronounced Open Four because it was developed originally at the same time as GTA IV but many people call it Open Eye Vee - so call it what you wish, just make sure to install it.
Click on pictures for full size
The next step: Installing OpenIV
Older process shown below
The next step: Installing OpenIV