Can a length of stay pass (six days, five nights at WL) be updated to an AP. If this is possible the cost should be pretty cheap. If so, tell me if this is possible or financially sensible. I book a package on dw.com with the length of stay pass, the first day I hit all 3 water parks (I've never been to any of them) after that i could upgrade to the AP then I have another year to come backand again the upgrade cost should not be too bad.