Very soon we will be updating your Epic account page at unrealengine.com with the ability to change your display name. In the meantime, we're pausing all display name change requests (except in the instances of inappropriate, real, or abusive display names).
Thanks for your patience. We encourage you to visit this new self-service option on your account page when it goes live in the very near future.
Please be aware that Epic display name changes only effect PC/Mac. To change your Twitch, PSN, or XBox Gamertag please contact Twitch, Sony, or Microsoft for assistance.