(I found this on torontomazda3.ca, so all credit due)
I was looking for a good spot to mount HID ballasts, so I removed the bumper. I was able to mount them directly under each headlight. So, if you need to remove your bumper for whatever reason...HID install, CAI install, whatever....these directions made it extremely easy.
1. Remove the 11 8mm (or phillips) screws on the bottom of the bumper.
2. Remove the two big phillips screws by the hood latch
3. Remove the two big plastic with rubber bumpers (use a small flat head to pop up the collar, then pull the entire thing out)
4. Take off the two plastic phillips clips holding the mud shield back in the wheel well towards the front. (per side)
5. Pull back the shield alittle and you'll see another 8mm screw by the bumper seam, take it off. (per side)
6. Bumper is now free but still hanging in place. By the hood latch will be two big hooks that clip onto the sub frame. After you slightly pull these up the bumper is now in your hands.
7. Remove the wiring for fog lights if applicable. And all other wiring. Set bumper aside.