Assuming you're on a PC:
- Go into the /game/ folder and find the /saves/ folder, and delete everything within the /saves/ folder, including the "persistent" file.
- Find the /RenPy/ folder - it should be under the /User/<USERNAME>/AppData/Roaming/ folder, find the folder named "University of Problems" within the /RenPy/ folder, and delete the entire "University of Problems" folder.
When you start the VN again, it will create a new "University of Problems" folder under /RenPy/, create a new persistent file, and then create new save files as you play and save.
Just don't go deleting everything within /RenPy/ unless you want to replay every VN you play from the beginning.