scupper change from floor to transom

[GodsReel]

I have a 76 23 cc with large floatation bracket and 225 yami 4. boat drains fine and does well until you have a coulple of big guys in back. Can i get some feedback from the guys who have gone through the transom without raising floor. ie how well it works, how hard it was etc. It looks like it will be hard to get in there but it looks doable without cutting floor. I have already recored some problem spots in floor . thanks