I did this on my Dart Sport ~20 years ago, so my memory is fuzzy on everything I removed. I do remember drilling a hole in the bumper shocks and securing them closed with some self-tapping screws. I don't remember seeing anything exposed that made it obvious that I modded the bumper.
That's even fewer years ago than I did mine, so my memory may be fuzzy! Oddly, I can remember doing it in my parents driveway, but not the exact method I used. I really had to dig deep in the memory banks!