How can i lower the graphics of my game without opening it?

So here’s the issue. My computer can only run Fortnite on the lower settings otherwise it crashes and shuts down. One of my mates came over and turned the graphics all the way up and it crashed my computer. But now every time i open the game again my whole computer shuts down because the graphics are maxed and i don’t get a chance to rectify it.

Try looking for .ini files with settings in the game folder and look for quality lines. Set their values to 0.