converting from i386 to amd64 without rebuilding

[Steve Lane <drsteve@rna.berkeley.edu>]

Greetings.  We've got a 4-core (2 x Core 2 Duo) server that was originally
built as an i386 machine, then converted to the i386 bigmem kernel,
and *then* converted to the amd64 kernel. None of the packages on the
machine, however, are from the amd64 port - they're all i386.

Is there some simple and straightforward (or even not-so-simple or
straightforward) way of converting the machine from the i386 port
to the amd64 port without rebuilding it from scratch using the amd64
installer, i.e. to reinstall all the i386-specific packages from the
amd64 repository?

Thanks,

--
Steve Lane
System, Network and Security Administrator
Doudna Lab
Biomolecular Structure and Mechanism Group
UC Berkeley