1. Click on the Window Icon (bottom Left).
  2. Click on Setting
  3. Click on Apps.
  4. In the search box, type in Ninja.
  5. You should see
  6. Single Left Click on it and it will expand, then click on Uninstall.
  7. Confirm the Uninstall, by clicking on Uninstall in the new pop up box.
  8. You will see
  9. And you may be asked to confirm that the APP can make changes, please click on Yes.
  10. You will now be asked once again, if you want to uninstall the application.
  11. Click Yes.
  12. You will then see.
  13. And then
  14. Click on OK.
  15. If requested, you may have been asked to install another version of that software, please see the document linked here for a guide.