There is a corresponding hole drilled in the surrounding 2x2 loose frames into which the wire fits. The wire is 1/4" thick, so drill the holes 5/16". The wire grid is 4" o.c. so that is the spacing. As the wire is welded in such a way that the horizontal wires are on top of the vertical wires, that places the centerline of horizontal and vertical 1/8" offset each way to the centerline of the frame. Pay attention to that detail or there will be a struggle. Measure carefully, and have fun.

That works for the horizontal pieces, but how did you do it for the angled pieces over the stairs? Those have wires going in opposite directions within an inch of each other.

that should be cutting to size , check out http://alidawire.diytrade.com

Is there a way to get more of a "close-up" of the frame/railings? This is exactly what we would like to do