This how too is for Silverado trucks, GMC trucks may be similar but not identical.
Only tools required are a ratchet, long extension, deep 10mm socket, reg 10mm socket, pliers, screwdriver.
First take notice of your headlight aim on a wall or something to verify upon reassembly that they are still aimed properly.
Get a towel and place it over your bumper so you dont scratch it in case of a mishap.
This took me about 1 hour to remove, install and take all these pics, so without a camera it shouldnt take longer than 30min tops.
First is to remove the plastic shroud held on by pushpin clips. Just take a flathead screwdriver and pry up on the centerpin...repeat this to all.
After all pins are removed lift off the shroud and place to the side.
Next is to remove the grille. The grille is held on with (4) 10mm bolts, one on each end and two in the middle....just remove those.
Next there are 6 metal clips that hold the grille to the center/bottom. There are four in the middle and one at the bottom on each end. I use a pair of pliers and squeeze the spring clip while pushing outwards gently till you hear it click a little. Just start in the middle then do the bottom left/right ones last...it should pop loose.
Dont worry about the grille falling off, it has two bent molded pieces in the middle that will prevent that.
After all this just remove the grille and place to the side
The drivers side headlight is held on with 4 bolts....two on top and one at each lower corner. You will need to remove the debris flap thats in the way of the lower bolt/bracket...take note of its position for reassembly.
Two top bolts
The lower bolt thats accessed from the front needs to be removed and the bracket rotated out of the way. This is some kinda floating bracket design.
The last bolt must be accessed thru the fenderwell. Just remove the lowest bolt and kinda fold the plastic liner out of the way and you will see the last bolt thats removed. Again...all of these are 10mm.