How do I remove the Malwarebytes extension from my MacBook Air?

Thanks for the help. I'd hoped getting rid of that extension would eliminate all the notices of viruses, infections, etc. Not yet. Bought Intego and run it to scan for junk, but .... Any other extensions I might have lurking and mucking things up by deceiving me about existence of bugs, viruses, etc? Or should I just stop worrying about what the notices warn about, since they're unreliable and deceiving?