Unpack contents of zip file to your Red Dead Redemption 2 main folder (the folder that contains the RDR2.exe).
Additionally you need to have Reshade version 188.8.131.521 installed to RDR2. I cannot include the Reshade distribution, you need to acquire this yourself through the proper means. Reshade can be downloaded from reshade.me specifically you can look in releases to find older versions
Good luck, I hope you enjoy this preset!