I did remove the carrier yes, but this was more for my own idea of how they come off. It actually slides off nicely when the window is secured and removed from the regulator. The only pain is the wiring loom in the door lock, a bit of a pain to release.
When the carrier is removed gives you chance to really clean the seals around the carrier and the door so that the new stuff will bond nicely. I also took the opportunity to suck all the water out of the door. I have noticed that someone has also replaced the seat speakers with a set of Kenwood ones and there was a massive gap around them. I have sealed this too so hopefully it will not let in water anymore.