1980 flt guestions

Hi, im new to the site. I have a 1980 flt tourglide shovelhead, trying to put it back on the road. This is my first Harley. My question is, is the oil bath for chain, primary, and engine oil all connected. Can I change all the fluids by draining the oil tank, or are they separate? How do I change oil in primary, and chain bath if not connected? Any info will be greatly appreciated, thanks in advance.