LRB Special Characters

I want to use Kal Jerico and Mad Donna, but how? How does my Van Saar find them in the Underhive? With the release of Underhive the rules for finding Special Characters from the old Outlanders have been left out, so here they are with some new flair…

Included Characters:
The Arch Zealot of the Redemption
Bonnie Annerson
Brakar The Avenger, He that Rains Death
Bull Gorg
The Caller
Dark Healer
Deacon Malakev
Drak the Hunter
Guilder Assassin Lothar Hex
Judge Malkavoy
Kal Jerico
Karloth Valois
King Redwart the Magnificent
Klovis the Redeemer
Mad Donna Ulanti
The Rat God
Scabbs