There are a couple of methods to do this:
My method was simple: when you do the Mavis case (the construction site ghost), go to 53rd & Lex, switch to Joey and leave the game running for a few hours (in my case I left it running for about 8), save your game when you return and then go forth with the rest of the game. It should pop up once the credits end and the bonus section appears
The other method I've seen recommended is to basically do the phone trick, going to Lauren's apartment have her light up a cigarette, pick up the phone, hang up the phone then rinse and repeat that process 100+ times.