I had to replace my grill recently. I also discovered earlier that changing bulbs is easiest to do by removing the headlamps. So, while changing the grill I also documented how to change the bulbs.
First you remove the hood stops, plastic rivets and hood release cable from the top of the grill.
Note: Mark where the hood stops meet the radiator support so when you re-install them they are at the correct height. Screw them in to the mark you made..
Next, un-clip the grill from the upper headlamp housing.
Pull out and up to release the lower clips around the headlamp. Don't be scared by how hard it seems you need to pull. It will be OK and is normal.
Note: Not shown in the picture but I put a towel in the area just in case the grill slips and scratches the bumper. Be careful.
The grill now just lifts off. Take note of the clips and centering pin along the lower edge. You will use them to line up the grill when you put it back in.
The headlamps are held in with three torx screws (T20 if I recall) remove them and the headlamp is free.
Reach behind the housing and unplug the headlight harness (mine has fogs so two plugs). Then you have a free headlamp housing to easily replace the bulbs.
Here is what the open cavity looks like.
Simply put it all back together the opposite of removal. All in all, takes about 20 minutes to do the whole thing. Even if you can get your hands behind the headlamp, you run the risk of either getting something on the bulb when installing it, or worse, don't actually get it seated right causing crud to get in your headlight. Now if you have fogs, there is no way you are reaching back there to change out bulbs.