I can't help with the manual , but I'll try to walk you through the winterizeing.
Ever winterize an RV before ? I need to know if you have any basic knowledge here.
Do you have an air compressor ? couple of different methods air is a big help for the real cold zones.
Have you checked the unit for low point water drains ?
Factory installed hot water tank by-pass ? Brand of water heater ?
I'm on the road for the next 2 days but I can get back with a full run through on the week-end.