Where exactly is the bumper damaged? The lower black plastic piece separates from the upper painted plastic piece. I've replaced two lower black plastic bumper pieces on two different Insight's where someone backed in to something and the upper bumper piece survived unscathed. This piece can be had for a modest price from Honda (I want to say around $80), and they keep them in stock in California because both times it only took 2 days to get one.
The bumper removal would best be shown with a service manual page print screen, but it's easy to get off. Most of the hardware is under the fender skirts and under the tail lights. You remove the skirts and tail lights, unbolt everything and and it comes right off. Then if your separating the two halves there's some more clips holding the two pieces together. The second time I did it I think I had the whole thing done with in a half hour.