Easiest, temporary way is:
create an ftp user in DA
open /etc/proftpd.passwd (pico -w /etc/proftpd.passwd)
find the ftp user you created, change the path /home/username to /var/www/html, you should have something like:
username:crypted_pass:uid:gid:system:/var/www/html:/bin/false
save and...