If I can add my 2 cents:

Pre-drill the holes in the mounting plate, then find the spot on the bumper where it sits nice and level and also centered on the "point" in the middle of the bumper.

Next, I used aluminum tape that is sold to be used around new door and window installations to hold the plate in place and to make sure it looks straight and even.

Hold you breath, pre-drill thru to the bumper and use 1 5/8 stainless sheet metal screws.

Dont over tighten!

It was scary, but worked out OK.

Good luck!