Trying to install yum per fedoralegacy.org/docs/yum-rh7x on RH 7.2 with rpm and related packages currently at 4.0.3.

Yum requires rpm, python, gnupg, and rpm-python - all at version 4.0.4. I have all those packages installed but they are all 4.0.3. The document provides instructions to upgrade to 4.0.4. Unfortunately, rpm of rpm-4.0.4... fails due to dependency errors: rpm-python 4.0.3 requires rpm 4.0.3, gnorpm-0.96.11 needs librpm-4.0.3.so, etc., with librpmbuild and librpmio shared libraries.

So I thought lets attempt to rpm -e the dependent products (except for rpm itself). Starting with rpm -e gnorpm, that was successfully erased. Next, trying to rpm -e rpm-python resulted in failure as that was needed by rhn-register-2.7.2-7.x.2 as well as up2date-2.7.2-7.x.6.

I need to install yum on a 7.2 system in order to download and install a specific package available only via yum.So what is the procedure that will let me update rpm and associated packages at one time so things will get done and I could then install yum?

Seems like I am in a catch 22. I know that I will eventually upgrade the release to 7.3 when a 7.3 version of the needed package is available. But for now, I have to get rpm 4.0.3 upgraded to 4.0.4! Help!

I don't know much about your situation, but I want to mention that you can install multiple packages at the same time; e.g. so you can try to install the packages you need and keep adding their dependencies until they're all satisfied