My sun roof will not retract (open). It will open in vent position. I did repair the wind deflector earlier. Any tips on accessing the mechanism to see what's jamming the opening mechanism? Do I really need to remove the headliner? I'm a competant shade tree mechanic, but its always easier when one has tips. I do have a copy of the service manual on cd, but its not clear if I have to remove the headliner. Or, g forbid should I just take it to the dealer to fix?