Due to the fact that Avira Free Antivirus for Mac is deep anchored in the Apple operating system, Avira provides an uninstall tool which removes cleanly the program from your system.
Navigate in the menu bar to Finder → Go → Utilities
Double-click on the Avira-Uninstall icon to launch the uninstallation wizard
(The Avira uninstallation wizard can be started as well by clicking Applications and dragging afterwards the Avira-Uninstall logo to the trash)
Confirm the deletion of the quarantined files before starting with the uninstallation
Authenticate with user name (with administrative rights) and password
Avira Free Antivirus for Mac will be removed from your computer