how hard is it to add silent choice to a trs boat with thur hull exhaust

does motor have to come out to hook up?

No. Bravo-Alpha thru-prop bilge exit is all the way under center of crankshaft. TR is on either side. took pics of my Pantera transom but can't add directly. but with exhaust, water hoses, linkages, etc removed you have fairly easy access to the 3 bolts attaching the plates. NOW: if you break any of those 6 bolts, the surgery to repair may well entail removing engine-trans and inner transom. at least this stuff is cheap. https://www.ebay.com/i/322391507987?...f719bfffdc86ef and i believe these would be the correct elbows. https://www.ebay.com/itm/W3-Mercruis...sAAOSwYo1cD9ki