How to Change/Restore Schema Password

To perform this you have to sys access. Connect as sys user into database and perform the following ...

SQL> select name,  password from user$ where name='ERP_PROD';

NAME                           PASSWORD
------------------------------ ------------------------------
ERP_PROD                  FD2C8A7959F2E1BF

SQL> CONN ERP_PROD/ERP_PRODpass
Connected.
SQL> conn /as sysdba
Connected.
SQL> alter user ERP_PROD identified by ERP_PROD;

User altered.

SQL> conn ERP_PROD/ERP_PROD
Connected.
SQL> conn /as sysdba
Connected.
SQL> alter user ERP_PROD identified by values 'FD2C8A7959F2E1BF';

User altered.

SQL> CONN ERP_PROD/ERP_PRODpass
Connected.
SQL> conn /as sysdba
Connected.
SQL>