I have used them many times - they are by the stroller rental in the front of the park. There is a kiosk to purchase and you have unlimited access to it throughout the day. There are 2 sizes and you pay a little more for the larger one but a change of clothes only should fit easily in the small one. If the kiosk is down you will have to go into the stroller counter and ask them to rent by hand. When we stay off site we often bring extra clothes to leave for cooler evenings, dry clothes in case of rain (usually brought a change if it was pouring in the morning so we could get comfortable when it moved out) and before they gave away ice water we would pack it with bottled drinks and snacks.