Your going to have to drill out, if possible, that last screw. That "cap closest to the window" is the Vent cover for the defroster. You have to get the Vent cover off to access the bolts that support the dash. After you get all that off there will be four bolts (two on each side) below the dash under the radio area, not hard to spot. there are some others, someone else can chime in on those. It also depends on what year you have and if its a 280z or 240z. The instructions I gave you are for a 280z the 240z might be different. Good luck!