You have to slide back the plastic to get access to the holes. Stick the button head screws through their holes, and slide the polycarbonate back into place. It hold the screw heads well engough to tighten the wing nuts, which are on the inside of the playing field. The 20 pt bar is a little loose…part of the game, but it won’t go anywhere.
Just as a reminder, the instructions say the wing nuts are to be on the outside of the field perimeter. If a team complains about them, then you might want to install them properly to avoid unwanted controversy.
We’ve already run our first qualifying tournament and had no issues/no comments about it. In fact, neither the head referee (who is really exceptional about details) nor the RECF person we had at the event noticed any issues. I expect problems will be unlikely. But the polycarbonate would have to be drilled for this installation.