I went snooping and I only found H05 in my files, not H06 anywhere. Because it's not a "real" stuff pack, it doesn't have the ability to uninstall it. I'm wondering this:
Looks like you had 2005 Mini pack then, if you have only H05 file.
a) get the H06 files off someone and add them to the correct folders and they'll appear in the game okay without any needs for installs
This method will work for 2006
objects, but NOT for
skins. Objects will appear without further ado. But to make Holiday skins appear in the catalogue, your base game Skins.package file must be updated by 2006 Holiday Stuff Pack installer.
b) is there some way I can go about uninstalling the pack without having to do a clean install to find an alternate copy that would have the H06 stuff in it and thus give me the outfits I am looking for?
You already acquired 2006 Holiday pack, right?
If H05 and H06 files are found in your Bins folder, the game thinks that Holiday pack is already installed. Deleting H05 and H06 bundle allowed me to reinstall 2006 pack "over the top" without uninstalling the whole game. Skins.package was properly updated too, restoring all missing Holiday outfits. I'm on XP though, not sure about Vista.
If all else fails, you can ask for updated base game Skins.package file from someone who already installed 2006 Holiday pack successfully.
@Ravenwings: SaraMK's ripped Holiday skins are built like regular CC, each mesh and recolor separated into a dozen different files. Downloading SaraMK's ripped outfits is not the same thing as properly reinstalling Holiday pack, or attempting to repair broken installation by adding missing files. Especially when I already own 2006 Holiday pack.