Just start Sudoku.py in the commandline with python Sudoku.py
There you will be presented with a preset board from settings.py.
The program comes with an integrated solving algorithm and the ability to change said preset Board using the "Board"-Button. Be careful not to use an invalid board as the algorithm can only solve solveable boards obviously.
The "Clear"-Button is used to reset the board to a completely empty board, which has to be changed accordingly to your needs.
The "Timer"-Button starts a timer which can be reset upon pressing the "Clear"-Button