How do I remove these grilles while avoiding damage to them and car's body/paint.
Use a hard plastic spatula or like tool, and gently pry up the corners, then the center. Good luck, they might break anyway.
I used two large zip ties and threaded them through each end. It took a few attempts but didn't damage the grille or paint.
I used a nylon strap to spread the load out. I ran it through each end and gently worked the grills out.
I used the zip tie method along with a block of wood and a pry bar. A zip tie was placed near each of the four pegs. I popped one side and then moved the zip tie near the other peg and extracted it as well. The was no damage to the grille nor the car. Thanks all for your help.
On the second grille I sprayed each peg with silicon lube as suggested on another thread and it seemed to help.