@marswill installed Carbon Fibre facia over the styrofoam behind the grill on his own car, which required removing, and more importantly, reinstalling the bumper. I would suggest checking with him for DIY tips.The side vents just clip in pull them straight out pull slowly the clips that hold them in break easy . The grill isn't held in with any type of clip the grill itself has tabs that clip into the bumper . It is possible to remove the grill without pulling off the bumper but you have to be careful if you pull on the grill you don't crack them .
The safest way is to remove the front bumper which doesn't take that much time to remove .