How do I downgrade an RPM on a machine without 'yum'?

Solution 1:

rpm -Uvh --oldpackage [filename]

--oldpackage allows you to install older versions, -U means "upgrade", but in this case it will just replace the other version. If you use -i instead of -U you will end up with both versions installed.

Solution 2:

You can also try yum downgrade packagename, depending on the version of yum on your system.