The push pins are tricky devils. You have to push in the center dot first and then the pin lifts out nice and easy. If you don't push the center in, you will break the pin. You will need to remoce enough so that you can lift the black plastic cover over the firewall, just under the windshield. On the passenger side is the AC filter box, it has a couple snaps that you lift and pull and then the door hinges open.
Once you know what you are looking for I would guess you could do this job in a couple minutes. Only tool you might need is a flathead screw driver to lift the pins.
Good Luck,
Jim Henderson