Please report any issues or bugs by contacting us at http://www.surfcanyon.com/contact.jsp . Changing the search engine in your Firefox SearchBar is as simple as clicking the icon at the left of the SearchBar.
UNINSTALL instructions, should you need them, can be found at http://www.surfcanyon.com/faq.jsp#q4 :
For the Add-on - Select "Tools", "Add-ons" and then click the "uninstall" button next to Surf Canyon. The add-on will be removed the next time you restart Firefox.
For the SearchBar - Click the Surf Canyon icon in the SearchBar in the upper right-hand corner of your browser. From the menu that drops down, select "Manage Search Engines...", which will take you to a menu where you can remove Surf Canyon.