I have a 35 horse Force model 357f7b serial 1918, its a 1987 model. It recently quit spitting water so I decided I would change the impeller myself after watching a few online videos. I CANNOT seem to get lower unit off. I have removed the 4 bolts that hold the lower unit to the piece above it and it drops 1/2 inch or so. I read online that you need to disconnect the shaft and on most outboards it appears easy to get to but not so with mine. I removed the exhaust port cover to get a little better access but I can not get to the shaft. I have removed anything and everything I can to try and get the lower unit off. I don't know what I'm missing and I can't find anything about the 357f7b online. Any help is appreciated.