1. Remove bonnet seal/weather strip, you just need to pull forward a little and pull up, it does take a little force to remove.
2. After you remove the bonnet seal, directly under it will be 5 Torx screws that you need to remove.
3. Now you have some play to pull the bumper forward and reach in there to get at the clips inside.
4. There are clips visible at the top of the grille, push the centre part of the clip down and at the same time pull the entire clip out, meaning pull the grille forward while pushing down on the centre of the clip.
5. Now do the same with the clips on the inside of the grille as you did with the ones on top. These require a little bit more elbow grease but it's really easy. The centre of the tabs require a bit of pushing in (and remember) to pull the grille out at the same time you're pushing in. What I would do is just take the tip of some pliers or flat head screwdriver (so you don't have to reach all the way in the bumper with your hand) and push the tip of it down on the centre part of the tab and pull the grille out at the same time to make life easier.
6. After you get the grille out, the new one just 'snaps' in. Do the same for the other side.