To use the program, execute the .jar in the cmd/powershell or just enter in the project folder and use it in your IDE of choice, and you are good to go! It's as simple as following the instructions printed and writing the specified data.
This project was created mainly for Java training and personal gameplay desires, I needed to know what were the best heists to grind, because most of the guides weren't applicable for me, with so many changes and variables that just become not practical to follow.
The Experience Calculator's part of the code was developed originally by nikolasb (github.com/nikolasb/Payday-2-Experience-Calculator), wanted to find a reliable and fancy coding that could become an implementation to my goal of making this the "Ultimate project" for Payday 2 math related subjects, and found his repository to be not just fancy and reliable, but also a nice project for studying.