Have to agree with MeMe take your time and make up a template before you cut the hole, i cut a hatch hole in the front of my consoul and someone suggested making a template, as it happens the guy i got the hatch off supplied me with a 1/4 inch marine ply template made up for that size hatch, which the hatch fitted perfectly into, i simply found the centre and offered up the template and drew around the inside then stood back and made sure it was in the middle and the correct place.
Then drilled some holes and carefully cut out the shape with a jigsaw, placed the hatch in and drilled through the pilot holes for the screws, the hatch was bedded into a nice bed of sikaflex and secured with self tappers to the consoul, worked a treat and looks great !!
Now when i came to cut out switch panels in the front of the consoul that was a different matter, after a massive battle with the steering wheel trying to get it off i gave up, and instead had to cut out the holes working through and around the wheel, this involved chasing the hole out with a drill and once i'd formed a hole cutting and filling the hole out to shape, took a bit of time but worked out ok and again as someone else said once the lip of the switch is bedded down you dont see the rough edges anyway.
Good luck and take your time, any error could cost you a lot.