If assistance was requested for your flight, an assistant meets you at the aircraft door or at the gate after landing. You are guided through passport control (for non-Schengen arrivals) and to the baggage belts, where the assistant helps retrieve your luggage, and then to the arrivals hall, taxi rank, train station or car park. Assistance at arrival is part of the same free service and the same booking you made via your airline before departure; it cannot reliably be arranged last-minute after landing, so book ahead.
Tell the person collecting you which arrivals hall to expect you in and allow extra time: assisted disembarking happens after regular passengers have left the aircraft. Your driver can follow the flight on the live arrivals board; see the assistance overview for how the service works.