Pretty straight forward and easy, but it involves removing the whole front bumper cover.
1. Remove the front screws (2 or 3, on each side) for the inner fender liner and push liner aside.
2. Remove the bolts that hold the bumper cover to the fender (2, on each side & near fender opening). I used a 1/4" ratchet with a long extension for easy removal of these bolts.
3. Remove the bolts on the bottom of the bumper cover (3, I think).
4. Remove the bolts on the top of the bumper cover, above the headlights (2, one on each side).
5. Remove the bumper cover from the car, you will have to pry a little bit at the top and the bottom to get it removed.
6. Once it's removed from the car, you'll be able to see how the grille is retained in the bumper cover. If the old one is trash, I would cut the clip portion off, as these are a pain to remove.
7. Re-install in opposite sequence. When you're re-installing the front bumper cover to the car, pay attention to the tabs (approx 2"wide x 4" long) that slide into grooves under the headlights. Also pay attention to how the bumper cover is centered and lines up with the fenders.
Hope this helps, I'm sure it's not totally complete, as it's coming from my memory.