winterizing 2008 Damon daybreak model 3578

I have a 99 Coachman i,ve had since new and winterize it every year by blowing out the lines with compressed air and pouring antifreeze down the drains.No problems in 14 years.A friend of mine just bought a 2008 Damon daybreak, model 3578.The water system is a little different than my Coachman. I am going to winterize it for her.Anyone with any knowledge of this MH and advice please let me know.Also she recently stayed at a campground with cable hookup.She could not get the cable to work and was told to turn the amplifier off for the antenna.She could not find it.Anyone know where it is? Thanks.