Have you tried downloading the gzipped tarballs (tar.gz) ftp://ftp.rpm.org/pub/rpm/dist/rpm-4.0.x
and install them.
1. untar and decompress the file by typing: tar zxvf <package-name>.
2. change to the directory it created usually a similar name to the package.
3. open up any text file that might give you any clues on how to set it up properly.