Undo the 4 bolts along the top. There are two screws holding the grill to centre bumper one at each side. you need to be on your knees looking upwards. You can remove the centre bumper as well if you want by removing the two bolts at the bottom.
Sounds and looks easy but doesn't work! I've taken out the 4 bolts at the top which are under the bonnet edge. There are 2 of those funny push in plastic connection thingies under the front which I took out and 2 bolts underneath. Ends up a bit lose at the bottom but still rock solid elsewhere! What am I doing wrong folks?
Once the four screws are removed you pull the panel up and towards you at the same time to disengage the clips down the sides. Then you need a flat screwdriver or wider plastic tool to lift the bottom part out of the bumper. They almost always pop out of the grille and sometimes break but as long as a couple are fit to go back in again the grille will sit securely.