[CentOS] RH9 to centos 5 386

I am testing the likelyhood of updating a couple RH9 systems to centos 5 
386.
I found at document that talked about updating to centos 4. steps being:
1.) backup
2.)
        rpm --import            
http://pubmirrors.reflected.net/centos/5/os/i386/RPM-GPG-KEY-centOS-5
        rpm -Uvh --nodeps       
http://pubmirrors.reflected.net/centos/5/os/i386/CentOS/yum-3.0.5-1.el5.centos.5.noarch.rpm
        rpm -i --nodeps --force 
http://pubmirrors.reflected.net/centos/5/os/i386/CentOS/centos-release-5-1.0.el5.centos.1.i386.rpm
        yum upgrade

Everything was progressing until I did tte "yum upgrade"
I got an error about not finding a yum package.

"There was a problem importing one of the python modules
required to run yum. The error leading to this problem was:
No module named yum"

What do I do now...

Thanks,

Jerry