Adapting Season Zero scenarios to PF rules

[Nefreet]

If you are running a Season Zero scenario, what leeway do GMs have in updating the encounters to Pathfinder rules? Obviously figuring out CMB and CMD are self explanatory, but what about class abilities that no longer exist?

0-22 Fingerprints of the Fiend Example (spoiler alert!):

The final boss is a 9th level Cleric of Asmodeus, and some of his 3.5 abilities no longer exist in Pathfinder (such as "rebuke undead", "turn water creatures", etc). Since he is commanding a zombie, I'd imagine giving him "Channel Negative Energy 5d6" wouldn't be too much of a stretch, right? Or do I have to research alternate Channel rules for dealing with "water creatures"? I don't want to leave him without any ability to deal with the PCs, but as he's written now he's just a divine spellcaster.

I checked in the GM Shared Prep folder and there were no updated statblocks available for him.

I'm sure this has come up before, but I can't find anything about it in either this forum or the General Discussion forum. If someone has a link to any previous discussions, they would be much appreciated.

Thanks in advance!

[Sniggevert]

As stated in the Guide, you figure out the CMB/CMD and change referenced skills to the new skills in PF (i.e. move silent/hide becomes stealth, etc.). These are the only two changes you're supposed to make to statted NPC's (outside of Bestiary critters that match CR's as indicated in the Guide as well).

In the case of abilities that no longer exist in PF, referencing d20srd during prep can tell/remind you how the powers work.

[Nefreet]

Totally forgot that was in the Guide. Thanks!

[Majuba]

You never know - PCs might

Spoiler:

summon a water elemental... in a dry subterranean cave... yeah n'mind :)

At least he's dangerous enough as it is. Wall of Fire is a great lead-in.