Most apps in Mac OS X can be uninstalled easily by dragging them into the Trash from the /Applications/ folder, and many others come with accompanying uninstall applications that will clean house and completely remove the apps too. Additionally, there are third party utilities for OS X that can make total removal of apps as simple as drag and drop.

Another solution, which is best reserved for advanced Mac users who are comfortable with the command line and have a deeper knowledge of OS X, is the thorough manual removal of an app and all associated components, and that’s what we’ll cover here.

Full article here:
How to Completely Remove Apps & Software in Mac OS X by Manual Terminal Uninstall (OS X Daily)