I have a 1983 Johnson 70 hp outboard. I have owned it for 4 years or so. I went to change the lower until fluid last weekend and the only thing I got out was water. I filled it and used it twice this weekend with no issues. My guess is I need to replace the seals on my lower unit. Is this something I should attempt myself and is it something one guy can do by themselves or is the lower unit removal a two person job. Any advice would be appreciated.