The upper grill has 9 clips that you turn 1/4 turn to release thier hold. There is also 2 clips at the top, by the headlights that require you to squeeze them from the back, and push through. Once grill is off, pull all clips off the truck and insert them in their places on the grill. To install grill back on, you simply line up the clips with the holes, and push them into place.
http://www.clubtitan.org/forums/vbpgimage.php?do=full&p=2726

The lower grill, or "Bumper Sleeve" can only be gotten out after the upper grill is removed. (at least I see no way to get it out any other way) You start along the upper edge. You will see 3 buttons. Pry those buttons out, then remove the inserts that the buttons are pushed into. You will then take off 2 self threading nuts from the side (1 on each side)that are screwed on plastic posts. Finally pull the top out as much as you can, from inside the bumper you will find 4 of those same nuts accross the bottom. Once bottom nuts are off, pull top out, working side loose at the same time.
http://www.clubtitan.org/forums/vbpgimage.php?do=full&p=2727

Just so you guys know my dedication, here is what it was like doing this, and the reason for the pics taken inside!

Bixll you are a brave, brave person to do that in the cold.

Believe me, I asked myself more then once what I was doing! I got my new grill installed, but aint takin no picture of it untill I can get truck cleaned up!

Buuuuurrrrrrrr!!!! Your crazy!!

Ohhh Bill......any pics of that grille yet? Thanks for the "how to", btw! I'll be doin this hopefully within the next few months.

Rocky he posted the new grill here http://www.clubtitan.org/postt1138.html
enjoy
m4ck

Does anyone know the part number for the 9 clips? Hopefully I only have to buy two.

thanks for the tips. i plan on doing mine as soon as i can get ahold of the oen no fear upper and lower grill for my 09 se cc