BMW Repair: sunroof repair, mechanical linkage, bmw dealer

Question
We bought a 1993 325i for our son last year.  He has never had occasion to open the sunroof except recently.  When he did, the roof only opened 1/4 way and then stopped.  I took it to the BMW dealer and they wanted to replace the roof and charge me $1300.00.  I believe I can repair it myself and I doubt I need a new roof.  How can I remove the headliner in the car to expose the roof mechanism?

Answer
the sunroof can be a dauntless task for those whom do not understand the system.  take off the cover for the sunroof motor and attempt to open the roof all the way,  if you get some resistance, it's possible that the linkage is bad or possibly the adjustment for when the motor should stop.  I do not believe their is a reason the entire sunroof should be replaced other than if the mechanical linkage has a noticeable fault.  should you opt to have it done, request from the mechanic the broken parts as to be sure he's not full of it.
-cheers