GTA IV: How to get the episodes

[trollzhxtroll]

I bought GTA 4 since a long time on Steam and someone said there is something called Ballad of Gay Tony. I really want this episode after watching some gameplay yesterday. I have the complete edition of GTA IV and I just can't find how to play it...

 

[COLGeek]

See here: http://gta.wikia.com/wiki/The_Ballad_of_Gay_Tony