The instructions below will walk you through the process of installing the X window system, GNOME desktop environment, and configuring VNC so that you can access it remotely.
yum -y upgrade yum -y groupinstall "GNOME Desktop Environment" yum -y install vnc-server
As a general rule of thumb you should never run X windows as root. In this example we will add a system user with the username 'colo' and configure X windows to run under that user.
adduser colo
Next you need to set a password for the user colo:
passwd colo123
Next we will drop down to the system user 'colo' using su and configure VNC. When running the vncserver binary you will again be asked to set a password. This will be the password you use in your VNC client.
su colo vncserver
Next you need to edit /home/colo/.vnc/xstartup and uncomment the following two lines:
unset SESSION_MANAGER exec /etc/X11/xinit/xinitrc
Next we want to restart VNC so the changes take affect
vncserver -kill :1 vncserver
That's it, you can now connect to your server using the server IP address with a :1 (the display port) at the end of it using your VNC client.