The recommended and described tools are:
For a howto for the installation, please look at the linked pages.
please refer to the linked pages for that
You have to export the private key so that it can be used with putty or WinSCP. Private key files have the file extension ppk with putty.
Do this by clicking the button Export private key and store that at a place so that you will find it. You have to tell putty or WinSCP to use this key.
In order to connect with WinSCP to aerocom-users.met.no, WinSCP has to use public key authentication. This means that it has to use the same private key as putty to connect to aerocom-users.met.no. Here's a basic howto.
If everything went well, you will see your home directory on aerocom-users.met.no on the right hand side of the WinSCP window.