Get the pack from a reputable source like GTA5-Mods.com .
Drag the modded update.rpf or settings.xml into your game directory or the specified OpenIV path. GTA 5 FPS Booster MOD Pack | How To Increase FP...
Specifically designed for older PCs, it can provide a massive 40–60 FPS boost by simplifying textures and lighting. Get the pack from a reputable source like GTA5-Mods