You can change supervisor passoward first using below steps 
and then change all the users passwords using supervisor.

 Warning: Direct manipulation of the repository tables can 
cause damage to your repository and will void your support 
contract. Do so at your own risk. 

If you don't have a second general supervisor, you could 
try the following SQL run against the security domain 
database: 
Code:
Update OBJ_M_ACTOR 
Set M_ACTOR_C_PASSWORD = NULL 
Where M_ACTOR_C_NAME = <username of general supervisor>; 


This will set the password for the general supervisor to 
null, and therefore the next time you login, you will not 
need to enter a password. It is recommended that a password 
is given asap via the supervisor module. 

You will also have to set the status of the user login, 
otherwise even with a null password BusObj will not let you 
log in. 

The status column is in OBJ_M_ACTOR and is called 
M_ACTOR_N_STATUS. If you set this flag to 1 along with 
setting the password to null then you should be okay. If 
this still doesn't work, make sure you have commited the 
database update