For this click on the Avast icon in the toolbar and select Open Avast Security. Steps to completely uninstall Avast Security on Mac Please, carefully follow our step-by-step guide to correctly and completely uninstall Avast from your Mac. If you have already uninstalled Avast before using the official removal guide, we recommend that you check your Mac for Avast leftovers. This may cause problems when trying to completely uninstall antivirus from a Mac. The first and most important thing you should remember is never to remove antivirus programs just by dragging them into the Trash. How to uninstall Avast Security on Mac using its default uninstaller How to quickly uninstall Avast from Mac.How to uninstall Avast Security using its default uninstaller.In this article, we will explain how to safely and completely uninstall Avast from your Mac. Besides Avast’s usefulness, you might need to uninstall the antivirus. Avast is an antivirus application that protects computers, helps them stay safe from viruses and hackers, and secures user’s privacy.