Here is the manual :

• download and run putty (~500Kb) from here :
  http://www.chiark.greenend.org.uk/~sgtatham/putty/download.html
• in "session", hostname, enter "lupus.aip.de"
• at the bottom, in Connection/SSH/Tunnel, check "remote port do the same"
• in "source port", enter 8008, in destination, enter "141.33.4.38:8008"
• check "Local" and "Auto" below these options
• click "add"
• click "open"
• enter username and password (for lupus I mean)
  Then you should just see a shell window, leave it alone -Now, in your favorite browser, enter "http://localhost:8008/halotracer"

And it works!