Scourge of the Howling Horde was meant to be a simplified introduction of rules mechanics to attract new players in some sort of last ditch effort.
I "Conan-ized" it. Howling Cave has become a hide out for a rival Cimmerian Clan, the Grath. I threw out the giant weasel, the young black dragon, the Shrieker, and the other D&D nonsense. Then, I replaced the Hobbies, goblins, and bugbear with Grath Barbarians and Hyperborean Soldiers.
I kept the guard dog and the giant spider. If I capture the PCs, they'll be sent to see "Mog", which means locked into the spider area that the NPCs have fenced off, and the PCs will be wearing nothing more than a loin cloth.
The ancient dwarven shrine has become a shrine to an ancient people long forgotten by the Cimmerians. Caves like this do not exist in Cimmeria--so this is a unique experience for the Barbarians in my campaign.
And, the undead that was in the Wizard's room--I did something neat with that. Before the PCs got here, they killed a few Grath along the way. Scouts and what not. Well, I had the Grath stand up from their death poses after a little while and just start walking.
The PCs don't know it yet, but where the dead walk to is the Wizard's room in Howling Cave. There, they'll see some men they've already slain, in zombie form.