Please use the steps below to uninstall Snagit on Mac.
To uninstall Snagit for Mac first ensure that Snagit is not running; once you are sure the application is not running go to your Applications folder (Command+Shift+A) and locate the Snagit for Mac icon. Click-and-drag the icon to your Trash bin and then Empty the trash. This will remove Snagit for Mac from the computer.
There is a short video below that shows this process: