I finally got the o-ring today from the parts store. I took the 2 nuts off of the lower unit figuring the bottom would just separate from the mid-section. Nothing budged. Are these two parts of the low end pressed on? or am I missing something that needs to be removed? Do I have to pull the prop and all that other fun stuff off to change this bushing? Thanks in advance for your help this is a great site full of knowledge! Oops I almost forgot it's a 1961 75 horse Johnson.