If you intend to stop playing, you can simply logout and delete the app, leaving your villages to be taken over by other chieftains.
If you want your information to be entirely deleted, please get in touch with our support team while you're logged into your account (Settings -> FAQ & Support -> Contact)
How to contact support (apple)
How to contact support (android)
⚠️ Please note: When deleting your account all account related data will be deleted irreversibly! ⚠️