Yes, there were several postings on this on the old system. There is debate on the actual coolant, and I ended up using the 50/50 mix from an auto parts store. It did say low phosphates, and I did not feel like finding deionized/distilled water, and mixing it first. I have done it twice, have 61K on my Connie, and no leaks, so I must have one possible way to do it.
The one thing to remember is, when that little drain screw is opened at the bottom, be prepared! 
It does not dribble out, it launches horizontal until it empties. I thought I was prepared. IIRC you are supposed to open the cap first. Even when open, figured there was no pressure. WRONG. It is just gravity, right? But with the small drain hole, physics is deceiving.
When drained, close the drain plug, and all hoses, then re-fill radiator. Fill up the plastic tank on the side to just the low point line. Keep the radiator cap off and run it for a bit to circulate, but don't let it get too hot. You should see bubbles on the surface of the fluid, and some fluid may spill out. Fill up if needed. Close the cap.
Now all fill adjustment is at the plastic reservior. Run the bike for a while to get it nice-n-hot until the fans turn on.
Check the level in the plastic tank and fill if needed.
One thing that was odd about mine was that the plastic tank actually lowered a little when hot, but I thought it would do just the opposite.
Take a look at section 2-50 of the service manual.
Good Luck.
