I lay it down on the control panel that has been cut, then trace the outline with a knife, like an exacto.
If you have Plexy, cut thru the wood or metal plate first, then the plexy. Put down your control panel and burst thru the middle of the holes first, then saw cut to the edges.
IF you make a small mistake, you have the buttons to cover it up, except with a track ball, they are a pain.