How to Unlink Twitch Account from Xbox One?

Xbox Broadcasting and Troubleshooting

Disconnect the Xbox connection from your Twitch account on your Connections page.
On your Xbox, select the Twitch app in My Games & Apps.
Press the menu button .
Select Manage app.
On the right under SAVED DATA, select the appropriate gamertag.
Press the menu button.
Select Delete saved data.

How do I Unlink my Twitch Account?

Go to Your Twitch Accounts.
Select Unlink Account next to the Twitch account you'd like to disconnect.

How do you See what Accounts are Linked to your Twitch?

After logging in, click on your Twitch username in the top-right corner of the website and then select “Settings” from the drop-down menu. When the new webpage loads, navigate to the “Connections” tab. You'll now see a list of every account connected to your Twitch page.