sure you can cut the floorboard. Use a holesaw. I tapped mine in when the convertor was out using a socket, drove it right in. Suppose a nut and washer could pull it in too.
See, I tried that
Even though the washers were heavy. And perfect outside diameter.....they crushed the inside part of the metal ring.
My only guess is that the bolt threads caught it going in because the bolt was too big..
I ground the area down where the seal hole is and was going to hit it tomorrow. Might just drill it for good measure but I don't see it leaking there again for the next 20 years.
