How to undo a merged-user installation?

[Svante Signell <svante.signell@gmail.com>]

Hello,

I recently installed Debian/bullseye/sid in a VM from a snapshot. After running
that image I realized the I got a merged-user installation.

As for now I have:
bin -> usr/bin
lib -> usr/lib
lib32 -> usr/lib32
lib64 -> usr/lib64
libx32 -> usr/libx32
sbin -> usr/sbin

Is there some way to achieve a non-merged-user system from the current
situation? 

The Debian Installer does not seem to have an option for a non-merged-user
installation. Is that true?

Thank you for your time!