I'm trying to change the default outfit for Mjoll.
I found the outfit under Items > Outif, deleted the bandediron objects and dragged in some orcish

In the NPC preview all looks good, yet in game she still has her iron on.

Anyone know why?

Have you activated the mod via the "Data Files" option in Skyrim's launcher?

Yes

I get an error 'WARNING: Bad w-value on orcish... etc, I assumed this was just one of the usual errors you get.

His inventory is a part of your save game at this point.

Ah! I see, any way to get around that?

Just in case, shot of the window.

http://postimage.org/image/r4bfeppjv/

Delete the armour you dragged into her Inventory, and change where it says default armour to Orcish. should work then.

Worked, cheers. I just had to exit the cell after changing default outfit to orchichnohelm.

Thanks!