Enable X11 on Server

Edit /etc/ssh/ssh_config
    ForwardX11 yes
    X11Forwarding yes
    Uncomment: X11DisplayOffset

On Client: (This is all I needed for Fedora). Start Terminal and connect to the SSH server which is enabled X11 Forwarding with

ssh -XC username@hostname

For CentOS: After connecting, input commands like follows. $ eval dbus-launch --sh-syntax $ export DBUS_SESSION_BUS_ADDRESS $ export DBUS_SESSION_BUS_PID