The glass can be removed fairly easily, but removal of the entire assembly will need the headliner removed. I removed the glass, treated the rust on the seal lip and replaced the seal several years ago. The design of the seal lip traps water and rusts. The seal is not meant to seal all the water out but reduce it so it will drain out the front and rear drains. One of my drains was blocked last year by a mud wasp nest that caused the roof to leak. The motor has a clutch that can be adjusted but I find the motor under powered and works best with engine on. I rarely use mine as it doesn't take much for dirt to create friction that slows/stops the motor. There's a switch assembly in the motor housing that stops the glass at open/close points. The motor assembly can be removed on it's own but there is a procedure to make sure you don't mess with the timing on re-install. Overall the sunroof is a pain, but the truck came this way so I had no choice.