Everyone in your party must be present and show their resort IDs (which now includes the name of EACH person in your room). The wristbands are attached to you by the CM after checking your resort ID (meaning they will not hand anyone a unattached wristband). Some threads have actually posted that the CMs are now asking for a picture ID along with your resort ID (for adults). As long as you have the hopper option, you can certainly go to another park and switch back to the late park, even after that park closes to the public. You can get your wristband up to 3 hours before the park's closing time. However, there have been a few threads saying that you can now get your wristband earlier, but haven't not read any firsthand accounts of that change in procedure yet. We did this in January and it went smoothly for us. There are many locations throughout each park where you can pick up your wristbands. Check your resort when you check in and they will give you a guide that will tell you which parks, the hours, the attractions openned, the restraurants open and where you can get your wristbands put on your party.