Im doing the body work & paint on a friends 66 dart gt. Found out that you have to take the rear window out to remove the outer stainless trim. Its held on by the inner window molding clips. What were they thinking ?
I'm not sure but you are right! You need to make a small tool. I made them from a paint can opener. Make an opening on one side from the open area. Gring off some material on the upper area to make a pointed arm.
Then slide it under the inner moulding and release the clips from the moulding sideways and then cut open the gasket. Can be bought from a vendor like Vans Auto or perhaps DMT.