Answer
To unlink: Go to EpicGames.com, log in to your account, and select Connections. Select Disconnect > Unlink under Xbox, Nintendo Switch, GitHub, Twitch, or the PlayStation Network.
How to Link and Unlink Epic Games Account to Xbox, PS4 and Nintendo Switch Consoles
How to Unlink Epic Games Account (2021)
How do I unlink an unverified epic game account?
To unlink: Go to EpicGames.com, log in to your account, and select Connections. Select Disconnect > Unlink under Xbox, Nintendo Switch, GitHub, Twitch, or the PlayStation Network.