Software you will need
sudo yum install twm
(on other distros, you may need other commands, or download source code and install it).
Specific steps ∞
1, Enter your Host name and port in putty.
2, Set port forwarding in putty Tunnels.
3, Start vncserver in the server side.
4, Install twm on the server side.
5, Start vncviewer in the client side by Real VNC viewer.
1, See SSH Port Forwarding on Linux for details about port forwarding.
2, See How to Remote Control Linux Server Using VNC through SSH Tunnel for details about starting vncserver on Linux server side.