I did it on my 2008 nitro 189 sport, 150 E-tec. GAME CHANGER!!!
I tried to do it myself. Removed the cable system and installed the new hydro helm/steering colum. I ran into an issue when I went to install the hydro cylinder mount arm. Hard to explain but couldn't get it back through the holes in the engine that the cable steering rod came out of(after some work). The problem was due to the length of the hydro mounting arm and the height of the two boat deck extensions that surround the engine. The height of the extensions created too much angle to slide the rigid mounting arm through. In my estimation I would have had to drop the engine and dont have that desire or ability.
I ended up taking to the local Cabelas and I think paid a couple hundred for them to finish. Love the change and my wife is thrilled with the ease of steering now.
I have Hydraulic in my 96 896 Savage and let me tell you I cruise around with my pinky finger on the wheel it’s worlds and worlds apart from cable ditch cable and go Hydraulic this should be standard IMO on all boats