Very easy to change oil and filter. Do a search for oil or change in the fx nytro section. I am sure this has been covered quite a few times before. Let me know if you come up with anything, if not I will tell you a little bit how to do it. Pretty much you take all the side panels off including the bottom belly pan and then drain the oil and replace the filter. It's as easy as that. Just know that there are two drain plugs.
I don't know much about the chaincase. I am sure you can search that as well, if not maybe somebody else can chime an explain how to do that.