You can't
U can't reset it
To reset Clash of Clans using iFile, first, ensure you have a jailbroken device and iFile installed. Open iFile, navigate to the directory var/mobile/Containers/Data/Application/, and locate the folder corresponding to Clash of Clans. Delete the entire folder to erase all game data, effectively resetting the game. After that, you can restart Clash of Clans to start fresh.
delete the game data files
you go to the android settings and it will tell you if you want to reset or delete
Check
You can restore you iDevice. That really works. I've tried it. Actually if you delete the app it will ask if you want to remove it from your Game Center. Just say yes, then re-download it and it should start you off fresh I have a full step by step here: http://clashofclansblog.paulbrucesamson.com/2013/09/how-to-restart-your-clash-of-clans.html The whole process takes about twenty minutes.
Transfer your account to another android phone and it wil start a new game
power on
If you factory reset your Kindle and then reinstall Castle Clash, your game account should still be accessible as long as it is linked to a cloud service or account, such as Google Play or Facebook. However, if your progress is solely saved on the device itself and not backed up, it will be lost after the reset. To ensure you retain your game data, check the game's settings for account linking options before resetting your device.
You can reset the phone if it is an android. Moreover there is an option of forget password. It can reset your password if you want to.
Click on a network and select forget
At the moment it is impossible to delete and reset your game. You cannot start a new game unless you play on another device (in which case make sure you are not logged into the same Game Center or you will reload what you already had). However, you can delete the app by holding your finger on the app icon for several seconds until it starts shaking. When it shakes press the X in the corner to delete the app.