bow mount qestion

[Alberta Dave]

On Saturday my wife (yes she was willing) and I purchased a new Targa 1900 with a 200 opti and a motorguide. I already own a 3700 pinpoint and would like to change mounts. I took off the access panel to find the hole maybe 3-4 inches tall reaching up into the top of the bow impossible. My question is are the nuts built right into the hull? Is it held down with wood screws? Or do I have to remove the whole top of the boat to get access?

Thanks