what is the proper grub2 update procedure when changing disks

[David Goodenough <david.goodenough@btconnect.com>]

In the old Grub1 days if I had a bootable disk die and I copied its contents
across to a new disk and wanted to make it bootable I followed a procedure
that ran grub, looked for /boot/grub/stage1, set root to that hd, and then
setup that hd, and I was done.

But now Grub2 seems to rely on UUIDs rather than device names and so 
this does not work, or rather needs an extra step.

So can someone point me to either an existing Howto which documents
the new procedure (I looked using Google but got nothing but the old procedure
above) or can someone outline the new procedure.  This is of course a 
request for a Debian procedure, I am running a nearly up to date sid.

Thanks

David