I haven't taken my own sunroof out since I'm under warranty, but mine had to be pulled to install the new a-pillar drain tubes that were kinked from the factory. Not sure how involved it is, but the shop foreman at my dealer said that's the only way to replace or reattach the hoses.

In the meantime you can do what I did while waiting for the hoses to get to the dealer. I used painters tape and taped the sunroof channel over. X5 could then sit out in the rain and not drip a bit. But be careful to not leave the tape on too long or the adhesive will be difficult to get off the paint (don't ask how I know.) Or park the car with the nose pointing uphill so all the water will drain to the rear tubes. Fortunately my driveway is sloped so I could do that.

FWIW- the sunroof drain hoses have been an ongoing problem for the X5. My shop foreman said it is extremely common which is amazing on such an expensive vehicle.

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'04 E53, 4.4 Sport
'97 E39 528i
'86 911 Carrera, track car
'96 BMW R1100R