I have a 2007 Tahoe. I bought the replacement bulbs (#3157) and took to UTube to find a how-to. Apparently, you have to open the wheel well cover to loosen a screw that will allow the headlight assembly to move forward a few inches. Then, you have to remove the headlight bracket screws up top plus the top row of fasteners across the radiator shroud in order to allow the whole thing to pitch forward so you can get your hand in behind it to get to the bulbs.
Sound right? Any easier ways in?