I don't have that model, but there should be a low point drain (a white valve underneath) that will mostly drain it. We (and I think pretty much everyone) find that the small amount of water left isn't a problem, as there is plenty of room for expansion (and we live in Montana, so we get hard freezes).
If you open the low point drain before your final leg home, you will get even more water out, but not all of it.
2018 Jayco 195RB
2014 Toyota 4Runner