how do you remove the plastic around the base of the sunvisors?
 

What is the procedure for removing all the plastic that is on the front of the headliner. It is the big piece that has the sunvisors attached to it and the sunroof/light switch assembly. I am speaking of my mom's 420SEL. Tomorrow I will have a chance and I want to see if it is the windshield gasket that is leaking. I is coming in from the top somewhere. There are water bubbles that form on the edge of the aformentioned pice when it is raining for awhile outside. The water even drops into the tray in front of the shifter and a little onto the shifter counsel wood.
Thanks
David