I’m not sure I was clear enough about the specific piece that broke off, so I included a photo showing the notch left when it snapped and a photo of the poorly attached piece. Both areas of interest are circled in yellow. The piece is now glued in place, but it wouldn’t seat precisely, so I suspect it’s a temporary fix. That said, the switch (particularly of the Z6) is quite soft, so it applies very little pressure. Still, is ideally like to replace the aperture ring that it’s attached to to keep the lens as robust as possible. I’m not going to suggest I’m ham fisted, but, we’ll, I’m ham fisted.
So, back to the ring - is it a difficult replacement? Is it a fairly straightforward process?