If you are using PigVision Online then press the buttons Ctrl + Alt + End simultaneously.  The below window should open. Just click on Sign out and the program will close and you will be logged off. Now you can open PigVision again and it will restart and be ready for use again

Note: If you just close the remote desktop PigVision will still be running and will open the same place where it was left.

If you are using a standalone version of PigVision open windows Job list and close PigVision there.