Apex Installation for 11g Instance
Pre Installation Tasks:
1. Create Tablespace for Apex Data and Files.
SQL> create tablespace apex datafile ‘//apexd01.dbf’ size 500m;
2. Ensure Shared pool size is atleast 100m (suggested 250m)
3. Download the Apex Installation Software from the below Link and move the software to server
Oracle Application Express 4.0.2 – English language only
4. Unzip the apex Installation software and change directory into extracted folder
1. Login as sysdba: sqlplus ‘/as sysdba’
2. Installation Command: @apexins.sql apex apex temp /i/
3. Admin Username Password Change:
Enter a value below for the password for the Application Express ADMIN user.
Enter a password for the ADMIN user 
…changing password for ADMIN
PL/SQL procedure successfully completed.