This config we shortly describe how to update/change sasl user's password. Firs, list sasl database to retrieve a list of all current users. If you know the exact user name for which you wish to change/update password that this step can be omitted:
# sasldblistusers2 
lubos@localhost: userPassword
radek@localhost: userPassword
Once you have located the user of the user you wish to change/update password then use saslpasswd2 to set new password:
# saslpasswd2 lubos@localhost                                            
Password:
Again (for verification):