It is not necessary to remove the bumper cover, I have had mine out several times for various reasons, It is much easier to remove the front wheels and the black plasic fender well splash guard ( the forward one with the door to reach the fog lights). Then you can see what you are doing from the bottom. Once the light housing is loose you just wiggle it out the front. It may take a little doing; just watch you do not break the mounting tabs.
Here is alink to the original methanol cleaning: clean headlights