Config Oracle HTTP Server to run on port 80

I copy this documents from this page:
http://askmeapps.blogspot.com/2008/07/some-steps-to-configure-oracle-http.html

1. Stop Oracle HTTP Server using Application Server Control, or with the following opmn command,
as the oracle user (not root)
# opmnctl stopall

2. Issue the following command as root: Log in as root.
Run the following command in the middle-tier Oracle home:
# cd ORACLE_HOME/Apache/Apache/bin
# chown root .apachectl
# chmod 6750 .apachectl

(Be sure to now leave the root login)

3. Update the Application Server Control Console with the port number:
Edit the following file L as the oracle user (not root)
ORACLE_HOME/Apache/Apache/conf/httpd.conf
Take a backup or httpd.config
cp httpd.conf httpd.conf_old_chg80
vi httpd.conf
replace 7777 with 80
Save and close the file.

4. Restart the HTTP Server, as the oracle user (not root)
# opmnctl startall

5. Ensure that Oracle HTTP Server starts and uses the desired port 80