[DonC]

I would suggest you pull the windshield rather than tipping it forward for clearance to the defroster vents.
Pulling the windshield is relatively simple and the only difficult part is the 2 screws that hold the center support in. Take those out first.
Don't remove the side supports so you don't have to worry about getting the correct angle re-established. Just pull the 4 screws in each side and lift the frame out from between the supports. You might want to have an extra set of hands to lift the unit out since it's fairly heavy and will tend to fall backwards once the 4th screw is removed from each side. If you have windshield wipers remove the arms before you start.
When you're ready to reinstall the unit put a rag over the depression for the center support until you get two of the screws started on both sides of the windshield then pull the rag out. The rag will help prevent scratches to the dash from the center support as you're realigning the frame in the side supports.
DonC