To know about how to deactivate Facebook then you need to tap to drop-down arrow and then choose settings. With this, the settings page will appear and then tap to settings. Here, click to deactivate your account. Choose one reason for deactivating the account. If you want, you can also add more details. When you are done, tap to deactivate. Choose deactivate now and your account will be deactivated. You will have the option to reactivate the account by signing into Facebook with old account information. Follow these steps and deactivate your Facebook account.