Hi,
I just replaced the driver's side vent and the reason I was replacing it was due to broken vanes (not just out of position, but broken.
So I was able to extract the old one without worrying to much about damaging it (Thanks for the tip A2Steve)
But why are you replacing them? is it a colour change or something? The reason I ask is that it MIGHT be possible to swap just the vanes and associated connectors. If yours are not repairable at least you can remove them in situ and see if you think you could manage it? It is possible I believe, JUST, especially if you use the old one to find out how they all fit and connect together.
Steve B