OK so now I’m going to show you how to mount your worksurface to your cubicle. So you are going to take that surface. Again you have these cantilevers that are going to support that work surface. Take that surface, position it right here on those cantilevers (you want to make sure you don’t drop it while you are securing it). Leave about an inch gap in the back for cords. Align those cantilevers. Now there aren’t any pre-drilled holes so when you screw this in you are going to be really just screwing it in where that cantilever meets the surface. Screw up through from the bottom and you are going to do that in all four locations where the hole and the surface meet.