First go to the Applications folder in Finder and look for the Smart Switch folder. Yep, it's in its own folder for some god awful reason instead of using the normal application package structure.
Double click the Uninstall.app from the Smart Switch folder and click Yes.
It will ask you to enter your password since some drivers are going to be uninstalled, so do that and click OK.
Once the uninstaller finishes removing the app click Complete.
The Smart Switch folder isn't automatically removed from the Applications directory so you can go ahead and move it to Trash now.