You can check in up to 4 hours before your flight departs, present your health documents, check in your baggage and collect your boarding pass. Then you can buy your bus ticket for AED 20 and head directly to Emirates Terminal 3, with regular bus departures throughout the day from 4:00 a.m. to 11:30 p.m.* When you arrive at the airport you can simply continue through to your flight.
*Bus schedule: 4:00 a.m., 7:00 a.m., 11:00 a.m., 5:00 p.m., 9:30 p.m., 11:30 p.m.