I did it and it was easy. Determine where you want the exhaust to exit. You need to remove motor and Y-pipe to install the block off plate. Buy 2 tips with integral no-burn flaps from Rex marine. Pick up four 4" elbows and an adequate length of 4" exhaust hose from CPperformance. Fresh holesaw and the green 3m tape so as not to chip the gel. Measure twice, then measure again. Drill from inside until holesaw bottoms out. Remove plug in saw, then using pilot hole drill from outside to minimize rough edges. Use stainless screws and seal the transom hole edges with silicone. This was my procedure, maybe there is a boat builder that can simplify or recommend a better way.