At least some (maybe not all) DCL Transfer buses are equipped with a lift. You want to make sure your reservation -- AND your transfers -- are noted as needing an accessible vehicle. Is the person in a wheelchair? Or they just need to avoid the steps? If the latter, there should be a wheelchair in the cargo hold under the bus which can be used to ride up/down.
Generally DCL transfers are the large coach buses, similar to Disney's Magical Express.
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