In case your username is not elm, replace elm in the following code with your username.
Open a terminal window, and type:
ssh elm@athena.dialup.mit.edu
Enter your password when prompted.
In the terminal window where you sshed into athena, type:
cd www
pwd
Copy the filepath you see -- this is where you'll put the contents of the website. For me it was:
/afs/athena.mit.edu/user/e/l/elm/www
Navigate out of ssh by opening another terminal or typing:
exit
Let's say the file you want to add to www is called index.html, and is in your Downloads folder, and your username is elm. Then type:
scp ~/Downloads/index.html elm@athena.dialup.mit.edu:/afs/athena.mit.edu/user/e/l/elm/www/index.html