Hi. I know this has been asked before but I can't find the thread so I am asking again. I am going in December and we have 8 day hopper passes. I might be interested in upgrading one or all of them to AP's. I know I can't do it at the resort and need to do it at a park, right???? My question is do I do it right away before using it or wait until I use one or more of the days on the pass. Can I wait until the last day? Does it make any difference when I do it?And does anyone know what the additional cost would be? Thanks, all.