How change character set of DB

This do-list is not supported by Oracle.

Do LIST:

sqlplus / as sysdba

shutdown immediate;

startup mount;

alter system enable restricted session;

alter system set job_queue_processes=0;

alter system set aq_tm_processes=0;

alter database open;

alter database character set internal_use IW8ISO8859P8;

shutdown;

startup restrict;

shutdown;

startup;