I have a serger singer about that age, I could copy the directions on how to thread it if that would be helpful.What make is it? My serger has the direction inside the drop down. you just follow the color line for each needle. really pretty easy once you do it a few times. I love my serger, so I bought another once recently, and it is not nearly as easy to thread as my old singer
Oh, and a pair of serger tweezers is a must to thread it with!