GRU has three levels for T1, T2, and T3, the middle level being the main level that connects all three after Passport Control and Customs. Baggage is on the lower levels. Going to T3 from the Starbucks in the food court will bring him in on the middle level in T3. Escalators are adjacent to the doors where one enters from the street or parking garage. Elevators are also available, but small capacity and often a line will form to use them. There are two sets of escalators that face each other. Whichever you friend uses, once on the lower level turn away from the entry doors and move towards the back of the arrivals hall. Then turn to the right and go towards the far opposite corner if you plan to meet by the recheck desks even if you don't use them. Otherwise, your friend can just wait with others who are waiting for people to arrive.