If there is an error with a template or you would like to stop using a template for your Shopify notification emails, please follow the steps below.
Navigate to Settings in Shopify -> Notifications -> Notification Type (Ex. Order Confirmation)
Select the notification type you would like to edit. Scroll to the bottom of the notification page and select the "Revert to default" button. This will revert your template back to the original default Shopify notification email.
Here is a quick video showing this process: