Hard ballast tank winterization

Everyone mentions disconnection your soft ballast sacks, removing them, and blowing out the lines. Is there anything you need to do if you have a hard ballast tank? I have the LS with the hard ballast in the back. How would I even blow the lines out on that since I don't even see where the line connects to the tank?

Thanks,

Garn

I used suck up a gallon of Afreeze or enough so that I could run it out the empty pumps to winterize them