I have a 2016 engine. I will be doing my first water pump change. This engine has a 25 inch shaft. There is a spacer used to change this engine to 25 inch. from 20 inch. shaft. Done by Yamaha at factory. There are 2 sets of bolts on each side of the lower unit. Which set of side bolts should I remove. The upper 3 or the lower 3 bolts?? I know about the trim tab bolt removal and the bolt hidden under the trim tab housing. Please advise. Thanks, Sullmate