Solution for making a password never expire

SQL> connect sys/secret_password as sysdba;

SQL> alter user sysman account unlock ;

-- SQL> alter user DBUSER identified by newpa$$word;

Next, change the profile limit to unlimited.

SQL> alter profile DEFAULT limit PASSWORD_REUSE_TIME unlimited;

SQL> alter profile DEFAULT limit PASSWORD_LIFE_TIME  unlimited;

Check the password expiry date 

 
SQL> select username, account_status, EXPIRY_DATE from dba_users where username='BURLESON';
 
USERNAME                       ACCOUNT_STATUS               EXPIRY_DATE
------------------------------ ---------------------------- ---------
BACMONIT                       OPEN                         UNLIMITED