To change hash you actually must download scenery again. You can't just change it in file with hash. This file is only auxiliary help and is provided to check checksum which was generated when the scenery was saved.
1. Close simulator,
2. Navigate to C:\Users\<username>\AppData\Roaming\OnRailTeam\TrainDriver2. You can use Windows+R and enter %appdata% and press OK to open "Roaming" folder
3. Open main_file.settings using text editor.
4. Find phrase: "GamePackHash":"000009" -it could be different number
5. Change value after : to "000000"
6. All official sceneries will be downloaded when you startup a simulator next time.
Remember! If you check scenery in the editor, when you leave you have to not save changes or hash will change again.