I don't know if you have a shop manual but there is information in it for removing the trim. The drip rails hold it on the sides of the roof. To remove the front roof trim, you must remove the windshield to access the screws. Personally, I would not remove the front trim unless absolutely necessary. Mine was removed when my car was painted. In the process the windshield cracked. After that it took 3 tries to get the replacement windshield installed leak-free. The front reveal mouldings easily bend and dent too. In retrospect, I would have been better off having the painter tape off the front roof trim and not remove it. Now, if you must remove it, just know all the extra work entailed. The roof trim under the rear glass is held on by spring clips.If I remember correctly, most (maybe all?) of the retaining nuts can be accessed from the trunk.