You can talk to him repeatedly for 1039 minutes and tell him 86 different things... usually that does the job. But often he will pull you into billieland, so you have to tell him not to if you just want him to pop out of the poster
You cant unless you happen to get billie pop out of one of your green day posters and pull you in... it slowly turns you into a billie yourself, and it hurts. Maybe you dont wanna go...