Peter, The water circuit that cools the engine is typically laid up with the same pink antifreeze. Some others state success by draining the engine cooling water for winter. See here for a recent discussion.
Barry, If there is no apparent drain and the hoses can't be easily removed, the domestic lines can be cut to install a bypass and drain. This is what I did on mine in that situation. Please don't ask how long it took or how much it cost. It's an investment OK!!!!