After the marking and cutting I finished out the opening with a round file first to fix any off shape and then 180 grit sand paper. notice the buttons got a trim for this window as they looked off after a trial fit.
Next was a window around the wheel. Tape up the area to be cut, and mark as designated. the trace on the tape was then moved to a piece of plexi.
The edge of the buttons should be taped together so the thin flex section doesn't break. Cutting was done with a good margin for fitting to the plexi. As when cutting the plexi there was extra left for a tight fit and a solid glue joint.