The update is pretty straightforward:
[root@e-smith]# rpm -Uvh horde-1.2.3-1esmith1.noarch.rpm horde-mysql-1.2.3-1esmith1.noarch.rpm imp-2.2.3-1esmith2.noarch.rpm
...then cd /home/e-smith/files/primary/html/horde, and do "sh scripts/database/dbpasswd.sh". That should be all you need to do.