The purpose of downpatching DMC5 is to enable default LRT and more consistent version of University Skip. It is still possible with the recent update but, not very reliable as it requires different setup. For Consoles you can just delete Installed Game Data and stop using internet for the update. This only works for physical copy as digital copy will keep downloading the latest version.
Download these files and overwrite them in your installed folder ( If you don't know where it's installed you can right click the game on Steam —> Properties —> Local Files —> Browse ). Some advices: