The WhoKnows browser extension can be uninstalled at any time. Here's how to uninstall in each browser.
Chrome
Click the Chrome browser menu.
Click More Tools | Extensions to view Extensions window.
Find the WhoKnows browser extension and click the Trash icon next to it to uninstall.
Firefox
Click the Firefox browser menu.
Click Add Ons to view the Add Ons window.
Find the WhoKnows browser extension and click the Remove button next to it to uninstall.
Finally, restart your browser to complete the uninstall.
Internet Explorer
Open the Windows Control Panel (not Internet Explorer).
Click Programs and Features (Windows 7 and later).
Find WhoKnows amongst the list of programs and click Uninstall.
If Internet Explore is open, you will need to restart it to complete the uninstall.