reciever hitch options for step bumper

[dsy1]

I have a step bumper with a ball mounted but would rather have a receiver hitch so I can use different size balls and swap them quickly. Does anybody have a square receiver like one of the ones shown below on a step bumper?

I assume the one with the plate attached could be bolted or welded under my existing bumper or the square hitch tube could be welded on top or bottom. Anybody done this?