How to Manage HR Notifications with Notification Composer

We're gearing up to implement Notification Composer and are having a little confusion surrounding our current HR Notifications. We've used the delivered process to convert AWE and AG notifications, but we also use a number of HR Notifications. Since Oracle Docs states that HR Notifications are to be created and existing notifications managed through Notification Composer, is there a method to convert these? How are the existing HR Notifications "managed" via Notification Composer? We've been searching but cannot find documentation on using existing HR Notifications with Notification Composer.