Install of this is fairly easy, but be careful or you'll snap the clips off the old trim (if you want to keep it that is). The top part has 4 screws to remove, and then I just gently squeezed the clips with small pliers to pry it off. Clip the new one in place and put the screws back.
The bottom piece I found troublesome. I found it easier to loosen the top of grille and push down on the 2 furthest-to-the-ends tabs whilst pulling it. You can then work across to the middle gently prying it out. New part just pushes straight in and looks great!