How do I add days to a Disney Resort ID card?

I will be staying at Disney World resort for 7 days. I understand I will get a resort ID for each person, including child. If I am going to stay more days in the area, not at disney resort, can I add days to the resort ID card? Where? Can I add water park option at the water park or only at a customer service counter? How much can be done at the resort desk instead of the parks?How do I add days to a Disney Resort ID card?
When you are staying on property your room key is your "key to the world". It will contain your park passes, meal plan, room entrance and ID for extended hours. Once you are no longer staying on property you will be provided a park pass with any options such as Water Parks you purchase with the ticket. The resort desk or concierge should be able to help you.

Have fun!How do I add days to a Disney Resort ID card?
everything can be done at the resort front deskHow do I add days to a Disney Resort ID card?
Second answer is better.