Connect to Amazon ec2 through GUI from ubuntu 14.04

How can I connect to Amazon ec2 through a GUI? I believe this requires setup of gui in the instance. I tried many links, right out of the first page, after googling, but I got stuck at the stage, where I have to use the VNC client to connect. Below is a sample client I am trying to use

Taking a sample amazon instance public dns

    ec2-<ip address>.compute-1.amazonaws.com

How can I connect using VNC,or tightVNc after all the setup has been done?