Booting Linux from Linux

[Victor Odhner]

I am about to install Kanotix rooted at /dev/hda6, with XP/ntfs on hda1 
and fat32 on hda5.

This is on my friend's ratty old PC across town (39th & Camelback), and 
I have to talk him through the process laboriously on the phone, so I 
need this as simple as possible.  But here comes the complication:

I want this to have exactly zero impact on the boot sector, to begin 
with.  So I will tell it to put grub on /dev/hda6, the root partition, 
rather than on the boot segment.

At the moment, the floppy is not working on the box in question, so I 
can't boot this installation in any of the normal ways.

If I boot up the Kanotix live CD, is there a command or sequence I can 
use from there to force a reboot on the newly installed kernel, and 
using /mnt/hda6 as the root?  Let's assume the new kernel is 
/mnt/hda6/boot/vmlinuz, I'll adjust as needed.

Thanks,

Vic