"The brackets have small "tabs" punched out that are supposed to sit inside existing holes in the body. I had to bed mine out a little more to make them rest properly, simply used a punch and a hammer to push them out a touch more till then fit in properly. "
DON'T DO THIS
The tabs are designed to rest EDGE TO EDGE with the factory sheet metal edge. The tabs are for alignment and in addition to keep the steps from moving over time.