I pulled ours off and cleaned inside. We have a 2GM20F and it wasn't bad. However I have a 1989 Hunter 30 not a 31. 2 bolts, an exhaust hose, and a water hose. I took the clamps off, removed the water hose, pulled the bolts then bent the exhaust hose around until I could get a screwdriver into the hose interface to get it to come loose. Going back together was a breeze. Don't forget to hook up the water hose. Don't ask how I know this.
Ken