Guys need some help on how I should
go about drilling new exhaust holes, should i do it from the inside or outside and what is the procedure. Thanks

You can do it from either side, If doing it from the outside you need to put a few layers of masking tape all around where you'll be drilling to be sure you don't mark up anything you didn't intend too. If your hole saw isn't deep enough to go all the way through you'll need to stop 1/2 way and pry out the 1st piece (either out of the hole saw or transom) If you already have pipes and did your measurements from the inside, just use a long 1/4" bit from the inside (at the same angle of the transom) to mark the spot on the outside...

I like to cut thru from both sides. Gives a nice clean cut, no splinters or chips

Also, in addition to the masking tape, run the drill backwards a minute or two when you first start, and this will help eliminate any chips when you start. Once you have a nice groove started, switch back to forward and hop to it.