Go to http://wiki.open-esb.java.net/Wiki.jsp?page=HowToRunIEPOnOracle and download the create_iepse_user.sql script.
Open the create_iepse_user.sql script and review the instructions.
The names of the tablespace, data files, user, and password include the string IEPSEDB. If you want to change this string to a different string, then replace all occurrences of IEPSEDB with the new string.
Connect to the Oracle database as a user with the SYSDBA privilege.
Run the create_iepse_user.sql script.