First, unpack this .rar. To install the OIV Package, you have to open your OpenIV program up. Next, you should see the OpenIV welcome page with a list of games, hit Windows under the Grand Theft Auto V tab and it should take you to your GTA V directory. Once you get to the directory, look at the toolbar at the top of OpenIV and click the tools tab. In the dropdown menu you should see package installer. Open package installer and then go to whatever folder you unpacked the OIV Package in, click the package then open it. After it gets opened, click "install" on the right side of the Package Installer's window and click "Install to mods folder" when prompted to and it will install. If you do not have a mods folder then I suggest you google how to set one up. 