[KLUG Members] SSH through a firewall

[bill]

I've got the classic "relative far away and you're a computer guy"
scenario.  My question is how to do SSH through a firewall.  

Relative runs a Win98 computer, unwilling to upgrade, only uses it for
"just a few things."  Uses a DSL modem. 

The system is regularly corrupted and slows down intolerably, after
which it's rebuilt, often over the PHONE.

My idea: bring an old box when I go out there (soon) and put a linux
firewall on it (I prefer floppyFW).  Then set up VNCserver on the Win98
box.  Thus, I could tell her to turn it on and leave it alone while I
VNC in and remove all the spyware/viruses, etc.

I think I can set up VNC and port forwarding o.k., but I'm wondering how
to set up the SSH tunnel.  Usually I set up sshd on a box behind the
firewall.  I won't have that option here.

Do I really want to set up the firewall with an ssh server?  I could set
it up to listen on an obscure port, I suppose.

What do you guys recommend?

kind regards,

bill