Careful if you do it yourself. On the later models it is part of a urethane
seal that actually adheres the glass to the car. Most places uses something like piano wire and two wooden dowels to sort of cut thru the urethane. Even being careful, sometimes the glass breaks when trying to pull it. Assuming you have a leak, if you know where it is, you may be able to shoot some urethane from the inside using an extended applicator.