Chainsaw Repair

I understand about the bearings but I don't understand how you get the rod end over the pin .

Now I can possibley see where you might be able to slip rod in  place on the side opposite end of the counter weight  and drop the bearings in from the throw side but then what keeps them from slipping out sideways ?I'm missing something here .

This is one odd design .The thing shows needle bearing mains both sides .Kind of  like an 020/200T with the roller bearing mains .I got no idea how they hold the side thrust unless it's got fiber thrust washers  in the mains  like the 200ts' which are the weak link in that design . Why good heavens the longer I look at this thing it's a wonder it holds together at all .