At the heck in desk you will see a line for check in AND online check in. Ou would head up to the online check in designated CM/area. They have a folder ready for you with your maps, KTTW cards, etc. When you complete your online check in you will indicate what time you think you will be arriving at.
Your mug credit(s) will be on your KTTW. At your convenience just pop into the food court area of your resort, pick up a mug for each credit, and "purchase" them. You can then beg

in filling them up.