Have you tried something along the lines of :

rpm -Uvh perl-5.6.0.*.rpm ?

If old directories remain, you can just go through by hand and delete 'em, that shouldn't be too hard.

Just removing it via RPM (do NOT do it by hand! =) might be hard, because a lot of RPMS depend on Perl (you could rpm -e --nodeps perl-foo, but that can be nasty)

Actually, RPM can be a pretty handy tool; I'd nab the source RPMS for Perl and do

rpm --rebuild perl-5.6.0.src.rpm
[download]

and then head to /usr/src/RPM/RPMS/[architecture]/ and do the -Uvh command described above.

Update I concur with tilly about this particular version, but the upgrade technique is the same for stabler versions =) also, make sure when you get SRPMS to get them for YOUR ARCHITECTURE (mdk RPMS won't necessarily work on RH and vice-versa)

HTH!

Philosophy can be made out of anything. Or less -- Jerry A. Fodor