This article explains how to link or unlink Facebook Chat when using the Yahoo! Messenger for Android app.

To link your Yahoo! Messenger and Facebook accounts:

1. Tap the Link to Facebook option located at the top of your Messenger List.
2. Type in your email address/phone number and password, then tap Login.
3. Tap Allow after confirming your account name.
4. You should see a message saying that your Yahoo! Messenger account has been successfully linked to Facebook. You will now see your online Facebook friends in your Messenger List.

To unlink Facebook:

1. Access Yahoo! Profile from a computer.
2. Click Settings.
3. Under "Linked Accounts," select Manage my linked accounts.
4. Click Remove for Facebook.
5. A confirmation window will pop up, click Remove.

Please Note: The Remove Link to Facebook option in Yahoo! Messenger for Android does not function in the current version.