I just took out an airbag dash. I suspect the bolts holding the non-airbag dash in are the same. There are six bolts holding the dash directly. There are 2 bolts on each outside end, as you found. Then, if you pop out the vent pieces on the ends and look up inside you will see a single bolt near each end that attaches the dash to the bar that runs across the front. You can get these bolts out with a long extension and a universal joint and socket from below the dash.
Bill