How to undo all changes made, to make system partitions be as before installing overlayroot?

[MarioCavero]

I read in a previous issue:

Just comment out "initramfs init.gz" in "/boot/config.txt".

But that did not work. Is it possible to undo all changes made to the partitions to make the system be as previously? If so, how?

Edit:
My main guess is that the fstab file needs to be changed as well. Right now mine is as following:
overlay / overlay rw,relatime,lowerdir=/overlay/lower,upperdir=/overlay/upper,workdir=/overlay/work 0 0

But I did not make a copy of the original fstab, so is it then not possible to revert this overlay state?