Its actually quite easy, had to do this myself.
1. unclip the top of the grill, plastic screws in place. I just popped these out. no need to unclip grill from bumper as this will come away with the bumper.
2. Look under the bumper and unattach undertray and inner archers(these are just clip in place and the tray is just two bolts.)
3. Then at each side of the bumper there is two bolts holding it in place. You can see them by pushing liner back. Undo bolts and as you are facing the wheel, pull bumper towards you and it will unclip.
4 bumper will come away and drop down. (you will need gto disconnect washer line for headlamp washers.)
5 The headlamp is fixed in bottom corner and on top where you can see it. You will need small allen keys to undo the charger unit from underneath the headlamp.
Dont think Ive missed anything, though was about 1yr ago when I did it to my 172. Really isnt that hard tbh.