• Copy the 32-bit datafiles to the new 64-bit Oracle home.
• Copy the 32-bit configuration files to the 64-bit Oracle home. 
• If your 32-bit initialization parameter file has an IFILE (include file) entry, then copy the file specified by the IFILE entry to the 64-bit Oracle home and edit the IFILE entry in the initialization parameter file to point to its new location. 
• If you have a password file that resides in the 32-bit Oracle home, then copy the password file to the 64-bit Oracle home. The default 32-bit password file is located in ORACLE_BASE\ORACLE_HOME\database\pwdSID.ora., where SID is your Oracle instance ID. 
• In the 64-bit Oracle home, add the _SYSTEM_TRIG_ENABLED = false parameter to the ORACLE_HOME\database\ORACLE_SID \init.ora file before changing the word size.
• Remove this parameter from the initialization file after the word size change is complete.

Start the database in UPDATE mode:  

SQL> STARTUP UPDATE;

You might need to use the PFILE option to specify the location of your initialization parameter file. Set the system to spool results to a log file for later verification of success. For example: 

SQL> SPOOL catoutw.log

Enter the following command to view the output of the script on-screen:

SQL> SET ECHO ON;

Recompile existing PL/SQL modules in the format required by the 64-bit Oracle9i database:

SQL> @utlirp.sql;

Turn off the spooling of script results to the log file:

SQL> SPOOL OFF;

Check the spool file and verify that the packages and procedures compiled successfully. Correct any problems you find in this file.
If you were viewing the output of catoutw.log on-screen, disable viewing now: 

SQL> SET ECHO OFF;