You mean a hole saw I suspect. I have my doubts about how well that will work. Those saws are designed for wood and other non-metallic materials and the teeth are larger than you would see on a metal saw blade. The center hole will get enlarged and the saw will wobble around making a very un-circular hole since the bumper is thin metal.
You could mark the 2 inch hole on the bumper with a marker. Then use a center punch to indent a series of centers around that. Then drill those with a smaller drill bit, 1/4 inch maybe. Then use a saber saw to cut that out and clean it up with a file. You want the top of the small drill holes to touch the 2 inch hole line. The skirt on the connector should cover up any roughness in the hole.
If you have a good 1/2 drill motor then you might find a 2 inch metal bit. It will not be cheap tho.
Or you might find a local welding shop to burn a 2 inch hole for you. They might even have the right sized drill and will drill one. Or try a machine shop.