These instructions are for the Blekko SEO Toolbar. If you have the Blekko Spam-Free Search Bar, see the instructions here: http://help.blekko.com/index.php/how-do-i-uninstall-search-bar/
For Firefox:
You can remove the blekko toolbar from Firefox by going to Tools -> Add-ons, and then clicking on “Extensions”. The BlekkoToolbar should be showing as one of your Add-ons. Click on it and you will get a button to “Uninstall” – click on that button to uninstall the toolbar.
For IE:
Go to your control panel and choose to “uninstall a program.” Choose the blekko toolbar and click on “uninstall.”

How do I remove Blekko toolbar if it does not show up in remove software window?
Hi John,
I sent you an email to get more information about this particular problem. Please check for that and respond if you can. Very sorry and thanks for letting us know about this.
cheralyn
I got the same problem — the extension page doesn’t show Blekko at all. Then ow do I remove the toolbar?
Hi James,
I sent you an email as well, but you can check out this page as well for instructions on how to delete the Spam Free Search Bar. http://help.blekko.com/index.php/how-do-i-uninstall-search-bar/ Please let me know if you have any problems. Sorry for any confusion or inconvenience.
cheralyn