The brackets are made from Simpson A33 Strong Tie stainless steel carpentry brackets. They are already bent.
Here is what I did to complete the brackets:
1. Cut down one leg of the bracket.
2. Add 1/2" dia hole for PIAA light
3. 5/8" dia slot for the mounting bolt to the existing bumper bracket
If I did this again I would make the slot 5/16" or 3/8" wide.
4. Chamfer the corners.
5. Paint them black.
I will post the template I used on the bracket shortly.
The small holes in the picture were already on the bracket when I bought it.
DSC_3641 by
Gregg.F, on Flickr