The relevant facilities are indicated in green:
01b Starting point DESY Tour, Seminars and Workshops on Saturday
05 Convention Center, Program on Thursday and Friday, Convention Start
28c Evening program on Friday
You can reach DESY main entrance by using the busline 1 (direction Schenefelder Holt) and leaving at station Zum Hühnengrab (DESY).
In order to leave DESY you would need to use the Side gate (on the far right) and take the buslines at the station Luruper Chaussee (busline 2 or 3), as the busline 1 is currently only driving in only one direction.