Never as written
Any prewritten adventure is tone-deaf to the needs of your group. Whenever you're playing from a book, find a way to make it appropriate for your table and bend the story to your style. I've changed a few things about A Wild Sheep Chase here — this is not a criticism of the original text, just a reflection of my style.
Better for newbies
Although A Wild Sheep Chase is designed for second tier characters, I think its themes and simplicity make it a perfect 1st level adventure for new players. I've adjusted the combat encounters for 1st level characters by following some advice from Luke at DM For Hire.
General changes for beginners
Use pregenerated characters. Work out PC relations in a 10-minute pow-wow before the game.
Pick a team name together. If a decision can't be reached, have an NPC give them a name during the session.
Don't punish bad tactics. New players tend to choose non-aggressive actions in combat like searching the room rather than fighting, so I give newbies an investigation check to find a healing potion where appropriate. This is to offset the extra relative damage they'd be taking and keep the squishy idiots alive (those lovable rascals).
Play on easy mode. Most tasks are DC10, though some difficult tasks go up to DC12. The final Arcana check is still a DC15.
Give DM inspiration early. This is to encourage creative play and skew the players' chances of success during A Wild Sheep Chase's final Arcana check with the wand.
Three NPCs in three scenes
Finethir the arrogant sheep
Finethir's goal is to get his wand back. He will promise PCs anything to do this, regardless of whether he can actually follow through.
Finethir has the self-obsessed and arrogant attitude of a master wizard, but his sheep form is adorable. Of the three sheep in that Simpsons episode where Lisa becomes a vegetarian, Finethir is the cutest one wearing a pink bow and jingly bell.
Finethir is presumed dead by the world at large. He had a reputation for being prickly about who he dealt with.
While with the party in combat, Finethir always acts on initiative count 1 and asks the nearest player character what to do.
Finethir considers the PCs expendable and always encourages violence against Noke.
Finethir thinks Guz is a useless idiot.
Finethir thinks Noke is a talentless hack.
Guz the loyal henchman
Guz's goal is to retrieve Finethir.
Guz is a handyman, groundsman, bodyguard and artist. He carries a paint-flecked key to his studio in one of the buildings at Noke's place. His art is awful — like, just so goddamn bad — but Noke always encourages him. Finethir would continually ridicule Guz's artistic failures.
Guz has no personal quarrel with the PCs, but will consider them enemies if they side with Finethir.
Guz thinks Noke is the Steve Jobs of turning things into other things.
Guz thinks Finethir is a bad berson. Guz enjoys taunting and humiliating Finethir.
Noke the jealous archanist
Noke's goals are to reclaim (or kill) Finethir and protect his power.
Noke's defining characteristic is his paranoia — he hasn't been sleeping and has developed nervous ticks.
Noke is more open to displaying his power than Finethir was. Noke trades with the wealthy, transmuting elaborate artworks for exorbitant prices. Noke created a marble statue of a witch shrugging in the centre of town.
Noke is distrustful of the PCs, considering them expendable meddlers.
Noke thinks Guz is loyal beyond doubt. Guz is the only person exempt from his paranoia.
Noke hates Finethir, calling him a trickster and a tyrant.
Scene 1: Guz is on the case
A Wild Sheep Chase doesn't include a setting, so I usually play in a town called Cradle. I describe Cradle as the ideal village — like the village in Hot Fuzz, but on the cliffs by the sea. In the centre of town is an exquisite statue of a witch shrugging made by Noke. I always ask the players where they want to start, and they usually pick a pub, the beach or a boutique shop.
After a few minutes of faffing about with a merchant NPC and showcasing the basics of roleplaying, Finethir charges in, bell a-dingling with this scroll in his mouth. When the players break the seal, the spell is cast.
A lot of this depends on the particular setting you've landed on, but these are the key points I aim for in this scene:
Finethir reveals he is a wizard and promises the players anything to get his wand back.
Guz reveals he thinks Noke is a genius, but is becoming more protective of his talents.
The large person in a hooded cloak isn't revealed to be a bear until combat kicks off.
Guz's goal is to get the sheep and leave — his actions in combat reflect this.
At half health, Guz and the bear will flee to reappear in the final battle if possible.
Scene 2: The middle bit
The transition between battles is a good opportunity to improvise some content and signpost elements of the final boss battle. As the player characters head towards Noke's, they come across a half-constructed outpost in the trees. Investigation reveals a pile of black goo with a semblance of ribs and organs mixed through — it's a failed transmutation. Finethir suspects Noke has tinkered with the wand too much.
For variety, this is a great opportunity to insert a skill challenge or puzzle. Write your own game. Go nuts.
Scene 3: Showdown with Noke
If anyone escaped the first fight, sub them in for some monkeys here. If there aren't any survivors form the first fight present and the players aren't coming in guns akimbo, Noke is willing to negotiate for the sheep. When the fight kicks off though, he bails. Maybe Noke sets off some kind of chemical explosion in the lab and fire to creep across the battle map.
This encounter can be tricky balance-wise. It's actually three separate encounters boiled into one — there can't be any overlap with these fights, or you'll accidentally trash the party. When the guards are dead, Noke transforms his bed into the splinter dragon. If you think the party can take it and you have time, have Noke transform into a functional gibbering mouther. Otherwise, he transforms into inert goo.
Contingency: Noke attacks the town
If the players hand Finethir over, you're in improvisation territory. It probably ends with Noke rocking up on a dragon-bed and leveling some buildings though. I've never had players hand over the sheep, though.