You have to do enough quests to get the attention of the Exchange.
This will trigger a cutscene where Visquis invites you to his private room in the Jek Jek Tarr. From there you will wind up gassed, gassed again, electrocuted, held hostage on a strange ship, hunted, lost, and found before finally meeting with Zez Kai El
If you can handle the spoilers, check Game Banshee's Walkthrough
for more details.