Ive managed to install TRD side skirt brackets successfully.
1st You have to shave off the mouldings under the seal panel with a sharp metal tool to make the holes appear. I used Toledo a Gasket scraper. How much you need to scrap off id say just a little bigger than the brackets themselves.
2ndly line up the skirts on the car where they are meant to be installed then thru the skirt screw holes you mark out exactly the spots you would be scraping off.
The brackets need to sit flush so it can clip into the holes thus they have to be scraped off clean from any mouldings.
I previously tried a 3D printed version, honestly don’t bother.
These brackets clip into those holes on the seal panel and they hold up the skirts firmly.