If your game is not connected to a Facebook, Google, or Apple ID account, all you have to do is clear the cache on your device (which can be done in your device settings) and delete the app. Next, download the app again, and the game will start from the beginning.
If you have multiple devices, you should disconnect the game that you want to delete from your Facebook, Google, or Apple ID account. You can disconnect it in the game's settings. Next, clear the cache on your device and delete the app.
If you deleted the game that was connected to your Facebook, Google, or Apple ID account and downloaded it again, then, when you open the app, you will be asked which game you want to save:
The game saved on your device, which has zero progress (since you just downloaded it)
The game saved on the server, which is the progress that you had before you deleted the game.
If you want to restart the game from the beginning, you must select the first option.
If you want to keep your old game progress, you should select the second option, type OK in the input field, and press Select.