I am looking at removing the trim and headliner but I wanted to know where to start. I am having a lot of trouble with the trim piece along the windshield and headliner.

 

In my 84 f250, that metal trim piece on the top of the windshield inside just pulls out, you might hafta reef on it pretty good and it'll pop out mildly violently. that's my experience. Same with the corresponding trim piece above the rear window and above each door.

 

nsshull is correct. There are metal slidable clips on the back interior windshield trim that firmaly hold the trim piece in place, the side trim pieces above the door and rear interior trim above the back window also have the clips. Becareful not to bend the metal trim piece when you remove it. The windshield pice has 3 of those clips on the back of it. Just don't "yank" one end as the middle clip may stick.