You can install this package with the command:
rpm -i pgp-5.0i-1.i386.rpm
If the link above does not work, then it's possible that a newer package of PGP 5.0 has replaced the 5.0i-1 package. In that case, you may have to try to use the PGPi download wizard to find an appropriate version.
If you are running an old version of Red Hat Linux, or if for some reason you do not wish to use a pre-compiled binary package, then you may follow the instructions below to build PGP from source code.