you can use your old handles by clicking on your round letter up by the upper right hand side of your screens .
then you will see 3 dark gray symbols next to your “current” username." a banner, a envelope, and an (options) star/icon .
CLICK on the star/options icon and PREFERENCES will appear.
you will see your current username. click on the pencil icon that brings up " Change Username " your can remove your actual name, and enter your older Den Handles, Then hit the update change button.