I have found that I can copy an existing entry in EFI, EFI/debian for example, past it in parallel with a new name, EFI/test, update-grub and when I reboot, I have a new choice to the same debian instance.
This suggests that I can now delete the debian instance, update grub, only have on instance to boot into the same instance. Then I should be able to install debian vai the installation disk. Here comes and experiment. I would like to than you all for your persistence. I will inform the everyone of my findings.
