Open your folder C:\Users\[username]\AppData\LocalLow\Live Motion Games\TrainStationRenovation\Save

Edit Autosave.save file with any text software (such as Notepad, Notepad++, SublimeText, etc.)

In the file, search for cash
"cash": (Your current balance will be here)
"cashBeforeChanges": (Your current balance will be here)
"stars": (Well, here are your stars)

Save and close the file.
Launch the game again