I am by no means well educated at removing the entire bumper, however I did loosen it and partially remove the under tray at the weekend to fit a CAI kit.
The under tray is screwed to the underside of the bumper, and arch liners this could be what you are referring too? I am pretty sure that the black strip at the base of the bumper is in place to protect the underside of it and act as a bookend to the tray? There should be a number of other connections, major ones at that, connect the bumper back to solid structure and the body ie there are six plastic rivets under the bonnet, which connect the bumper back to the core supports.
What makes you think that it has been "f**ked up", is it hanging off? There must be a post on the forum that illustrates how to remove the entire front bumper, maybe cross reference with that, which in-turn should enable you to locate all of the fixings?