removing the rear bumper on a 1964 dart?

Tip: Spray the bumper bolts (nuts backside) with a good penetrating lubricant. Do this a few times... wait, remove the nuts with a combination wrench of the right size. Do not remove all of the bolts, have a helper hold the one side of the bumper. Then remove the remaining bolts, puller bumper straight off. Usually, four or six bumper bolts and they could be different length depending how many brackets they go through. And yes, check for license plate light bracket and wiring.