How to Change Oracle Database Character Set to Arabic

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 AR8MSWIN1256;
SHUTDOWN IMMEDIATE;
STARTUP;

Oracle Developer 
Ahmed Arafa