1- Launch ReShade-VulkanPatch.exe

2- Browse to where your Red Dead Redemption 2/RDR2.exe is located, select it and then click Next
3- Select Vulkan and click Next

From there you can cancel and leave the installer or close the window, you do not need any shaders or anything else.

4- Finally simply move ReShade.ini and the CLEANLIGHT folder to where your Red Dead Redemption 2/RDR2.exe is located. 
Accept overwrite if asked. Delete the same file and folder to uninstall.

Have fun !
L00
