If you have access to the device the game was originally started on you can use this device to Reset the game (Click Here for the article) If you do not have access to the original device the game was started on you will need to delete the game from the administration portal and re-add the game to the fixture.
Note: Before deleting the game please ensure you take note of any line-up information already entered, as this will be lost upon deletion and need to be re-added back into the new game.