Just happened to have forgotten a password for one of my user accounts on my workstation and remembered a handy little thing one can do to reset a pass.
If you have root access, one can simply regenerate the MD5 hash with:
# openssl passwd -1 -salt mysalt
# ftp localhost
Connected to localhost (127.0.0.1).
220 Welcome to the Crazy Town . If you are not an authorized user, please logout now!
Name (localhost:root): tom
331 Please specify the password.
230 Login successful.
Remote system type is UNIX.
Using binary mode to transfer files.
and replace the existing hash string in proftpd or any other service with what ever is entered as a pass above. This should help to reset your pass.