The easiest is to go to the internet helpdesk (right above Guest Services on Dream and Fantasy). They will change the settings for you. Wait until the first evening, before they close, and the line should not be a problem.
To iPhone users, please note that iCloud can be a nightmare for cruisers. If you have it enabled and are not using it, I'd make a backup of my photos and get rid of iCloud long before the cruise. Otherwise, you can end up in a situation where you will have to choose between 1. losing all photos stored on your iPhone, in particular any that you might have taken on your vacation prior to the cruise, 2. not using the internet at all while on the ship, or 3. wasting most of your data packages having your iPhone constantly uploading photos, you take on the cruise, to iCloud in the background. I had to go with the third option which literally cost me hundreds of dollars in wasted data packages. I work with IT professionally and hate iCloud like the plague.
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