i had to change one reflector due to some idiot felt jealous and decided to break the reflector, which left me with a gray panel. Any how
i changed it without taking the bumper completely off, it was a little difficult, but it can be done.
there are two srews on the side of the quarter panel (behind the rear tire) that get removed, then there are 2 round plastic fasteners located at the bottom of the quarter panel, that get pulled off.
after that i basically held the side of the bumper back and wrenched off the nuts.
tip: before you install the new reflectors run the nuts on it first, then take them off, and install the reflector, the nut threads the reflector and you tighten it. just makes it a little easier to install.