github.com/PCSX2/pcsx2/issues/2106#issuecomment-356480660
Download the file you get from the workaround link, and install using the bat. It'll bring up a cmd and then close it quickly, but don't worry.
After that, you should be able to use ReShade with PCSX2.
This worked for me, so if you have issues, you are 100% on your own.