Unfortunately, my wife backed into someone and damaged the rear bumper cover (left quarter panel and center section). The rear bumper cover comes in three sections. The left and right quarter panel and then the middle section. The middle section also comes with the step pad attached. I had Precision Toyota Collision Center in Tucson, AZ do the repair on it, so I did not see it in sections. (They did an excellent job by-the-way.) AFAIK, you take off the entire bumper cover and then take it apart from there.
On my 04 I had the silver center piece painted. When I repaired the vehicle, I had PTCC paint the center piece the same color as the vehicle. At the same time, I also had the front bumper cover center piece painted (that was silver painted) the same color as the vehicle. I never did like the silver center sections in the 03-05s. The vehicle looks a lot better with the silver gone.
Couldn't give you a price on it, but if you're interested, you (@Trevloc) might run it through JC at PTCC , and pick his brain on it. I'm sure the rear center panel can be painted by one's self; it's fairly easy to do, however, I would be careful with the quarter panels cause they slide up and lock into place (it's a breakaway design, no screws, no pushpins, etc).
PTCC charged me $100 to remove, paint, and replace the front piece. Can't remember the rear piece pricing. My total bill was about $800 because I had to replace the left quarter panel, the center section, and then I also painted the right quarter panel to match.
Perhaps someone that has taken off the rear bumper cover can provide more info.