This procedure refers to the built-in icemaker in the Dometic refrigerator.

Pull the cover off of the ice maker.  You will see a large gear and in the middle will see a screwdriver slot.  With AC power to the coach and the icebox turned on, gently turn the screw counterclock wise (I beleive the gear will only turn one direction) until the ice maker starts it's cycle.  Do this a couple of time and the water will be purged from the water lines.  You can either use RV antifreeze of just use an air compressor to blow the water out.  IF more details are need email me,  
-Submtted by Gene Hamelan, aka G-Man.