Go to openiv.com and download the latest version. OpenIV is the only legitimate tool that allows you to open, edit, and replace files inside .rpf archives. It is approved by Rockstar (as long as you don't use it for GTA Online).
If you are replacing specific "pieces" (files) within x64r.rpf to improve quality, follow these safety steps: gta 5 x64rpf all files extra quality
Locate the specific texture or audio files you wish to upgrade. Drag and drop the "Extra Quality" files (usually for textures or for audio) provided by mod creators into the archive. Common "Extra Quality" Mods for x64r.rpf If you are searching for the actual content to put this file, look for these popular projects: GTA V Realism Go to openiv