You're supposed to locate the boss in the roof for the shoulder harness before installing the headliner, but we can work with what you've got. Feel along the roof, through the headliner, at about the rear edge of the door. You will feel a raised area, with a tapped hole in it. Make an "X" cut over the hole, and you will have the shoulder belt mount. The hanger mounts over about the middle of the door glass span, at close to the same level of the belt anchor. This will be harder to locate, and may result in you having to partially disassemble the trim and headliner at this point. More "X" cuts over the fastener holes will get you what you need, here. Look at as many cars and pictures of this installation as you can, before you do anything! This comes under the "measure twice, cut once " rule. You can save a lot of grief by going slowly and carefully on this.
