We have several tickets with days still on them from years ago and were hoping to combine them with new tickets so we don't have to spend as much this year. (We checked them on a previous trip.) The complicating issue is that one is a child ticket and both kids are now "Disney adults". Can this be done at home or do we need to do that at Disney? We want to be able to do all our fast passes at 60 days. Or should we just continue to save them for n future trip? Thanks!