You can remove Yahoo! Toolbar just like any other Firefox Add-ons (also called Extensions in older versions of Firefox).

Here are the steps:

1. Click the Tools menu at the top of the Firefox browser.
2. Click Add-ons or Extensions in the Tools menu (depending on which version of Firefox you have).
3. In the window that opens, scroll until you find Yahoo! Toolbar and click on it.
4. Click Uninstall.
5. Click again when you are prompted to confirm.
6. Close the Add-ons Manager or Extensions Manager, and restart your browser.

If you need further assistance, click the button on this page.