It's not too difficult....I just did it tonight. There are 4 phillips screws on each side (3 in the wheelwell, one on the bottom) and one phillps screw in the middle bottom. There is one bolt (5.5mm or 7/32) on each side behind the corner lights...yes, you have to remove the corner lights. There are 2 nuts (13 mm, I think) on each side that hold the bumper to the fender, from the inside. There are 4 plastic push connectors holding the bottom of the cover to the bumper. I think that's it.
The hardest part for me is the last thing....where the cover slides into the bumper (between the headlights), you have to "pop" that out. My tabs aren't very worn down, so they are a pain to pop out. I usually get one of my bigger screw drivers and gently pry the gap apart a little.
Oh yeah, it helps to have a helper.