Typical shared shuttle service. Not sure on the pricing if you're not technically going round-trip (KV-IOA-KV or YC-IOA-YC), but you just call the KV operater at least a day before you want to go to IOA and make your reservation. They'll tell you where and when to meet the shuttle. You pay for the trip up front and you'll be given return passes before you get off the shuttle. The driver will tell you to call a certain number two hours before you want to head back to Walt Disney World.