Rear bumper removal, help?

Hi folks, random question,

I got hit in the rear, and now my bumper is scrap, id like to replace it myself, im pretty inclined, but I am not quite sure how to do it. Im gonna futz with it tomorrow with a pal, but Im just interested if there is any tricks that aren't obvious.

Thanks folks...oh, btw, i just built my own CAI the other day, and wow, it works a lot better than i thought for something that looks like it belongs under a kitchen sink, haha

Thanks all