You can mount in on the starboard transom, with an adequate backing board of course. Or you can make the hole larger by cutting up a few inches... the motor cowling will interfere with the hatch cover when kicked up so there will need to be a modification there. You might want to reinforce the backstay's chainplate area also.
Or, you can do what I do. I remove the cowling and cover the motor with a canvas boot when I'm not using the boat. When I'm out sailing, I leave the motor in the down position. Only time I've ever kicked it up while out in the water was for racing, and it's kind of a pain. If I race now, the handicapper makes a 5 second adjustment for the prop, so it really doesn't matter.