Ok, so I had to download the installer several times because each time I install oculus it has to redownload so I got fed up and I copied what it downloads so I don't have to wait for it to download 5+GB of stuff every time.
Instructions: Just extract the .rar and copy the folder "OculusSetup-DownloadCache" with all the files inside of it to your C drive, then open the Oculus Setup executable. It'll verify the data and start the installation.
I made the backup a few days ago, the 6th of September. It might get outdated soon but so far it's the latest version. Besides, a small update is a few MB, not 5GB.
Enjoy, since Oculus still doesn't listen to customer feedback we have to do the s%it ourselves.